Short answer: it depends on what kind of line you actually need. Most people typing "how to add lines to a chart in Excel" mean one of six things — a new data series plotted as a line, a trendline showing direction, an average or goal line that runs flat across the plot, a reference line marking a date or threshold, a line floating over bars in a combo chart, or drop lines connecting points to the axis. Six lines, six different right-click menus.
This guide walks through all six. You'll see exactly which menu to open, what to click, and what the result looks like. We'll cover Excel 365 first (where most of the modern shortcuts live) and call out the spots where Excel 2019 and 2016 behave differently. You'll also pick up the formatting tricks that separate a chart that ships from one that gets sent back — dashed versus solid, color contrast, line width, markers on or off.
If you came here from a broader how to make a graph in excel search and you don't have a chart yet, build the base chart first, then come back. The methods below all assume you have a chart on the sheet you're trying to enhance. For a quick refresher on building from scratch, the dedicated create chart with excel walkthrough has the click-by-click setup.
One quick promise. By the end you'll know exactly which method to reach for when somebody says "can you add a line to that chart by Friday?" — and you'll do it in under thirty seconds.
Let's start with the six types so you know which section to jump to.
Adding a new dataset over the existing chart? Right-click the chart → Select Data → Add. Showing the direction of one series? Right-click that series → Add Trendline. Showing a single flat threshold (average, target, budget)? Add a helper column with that constant, then add it as a new series. Showing a vertical line at a specific date or x-value? Use an X-Y Scatter series with two points. Plotting one metric as a line on top of bars? Change Chart Type → Combo. Connecting points down to the axis? Chart Design → Add Chart Element → Lines → Drop Lines.
A second (or third) line plotted alongside the original. Use when you want to compare two metrics on the same chart — last year vs this year, sales vs target, region A vs region B.
A calculated line showing direction or fit. Linear, logarithmic, polynomial, moving average, exponential, or power. Read the equation and R-squared right on the chart.
A flat horizontal line marking a constant value across the whole chart. Built by adding a helper column filled with the average (or goal) and plotting it as a second series.
A vertical or horizontal line at a specific x or y value — typically marking an event date, a threshold, or a milestone. Built on an X-Y Scatter overlay with two anchor points.
One series shown as a line on top of bars (or columns). Most common pattern: monthly revenue bars plus a running line for cumulative total or a line for target.
Thin lines from each data point down to the category axis (drop lines), or connecting two series with white/black bars showing direction (up-down bars). Both add via Chart Element.
This is the workhorse method. Your chart already plots one column of numbers, and you want to drop in another — maybe last year next to this year, or actual against forecast. The whole job takes about thirty seconds once you know where the menu lives.
Right-click anywhere inside the plot area of the chart. Choose Select Data. The Select Data Source dialog opens. On the left under Legend Entries (Series), click Add. The Edit Series dialog appears with two boxes: Series name and Series values. Click in the Series values box, then go select the cells on your worksheet that hold the new numbers. The dialog shrinks while you're selecting — that's normal. Hit OK. Hit OK again. The new line appears on the chart.
If you'd rather not click around, you can type the range. In the Series values box, type something like =Sheet1!$C$2:$C$13. The exclamation point is required when referencing another sheet. Excel updates the chart the moment you press OK.
For line charts the X-axis is shared across all series, so you only specify Y values when adding a new series. For X-Y scatter charts you specify both — the X box and Y box appear separately in the Edit Series dialog. That's how scatter charts let you plot completely independent point sets that don't share any axis category labels.
Two things usually go wrong. First, you might be on the wrong chart object — clicking outside the plot area sometimes opens the worksheet menu instead of the chart menu. Click squarely inside the plotted lines, then right-click. Second, the new series might be using a totally different y-axis scale (say, $5 alongside $5 million). It's there, but invisible because it sits on the same horizontal line as zero. The how to add a secondary axis in excel section below fixes that.
Back in Select Data Source, you can rename a series by selecting it and clicking Edit. You can also reorder them with the up/down arrows. Order matters — the topmost series in the list draws first, so series further down in the legend visually overlap earlier ones. If a key line is hiding behind another, move it down in the list.
A trendline isn't real data. It's a math line Excel calculates from your existing series. Use one when somebody asks "where is this heading?" or "how strong is the relationship?" — sales over months, calls per agent, anything where direction or fit matters more than the bumpy raw numbers.
Right-click directly on the series (the actual line or column on the chart). Choose Add Trendline. The Format Trendline pane opens on the right. By default Excel adds a Linear trendline — straight line, best-fit through your points. For most monthly business data, that's the right pick. Done in two clicks.
The Format Trendline pane lists every type. Linear draws a straight best-fit. Logarithmic curves steeply at first then flattens — fits adoption curves and viral growth that saturates. Polynomial bends to follow waves — set the Order between 2 and 6 depending on how many bumps you want it to follow. Moving Average smooths volatility — set Period to 3 or 6 for quarterly or half-yearly smoothing. Exponential compounds upward — fits compound interest and unrestricted growth. Power works for relationships like distance vs time that follow a power law.
Scroll to the bottom of the Format Trendline pane. Two checkboxes: Display Equation on chart and Display R-squared value on chart. Tick both. The equation appears next to the line — useful when you need to predict future values by hand. R² is the goodness-of-fit number between 0 and 1. Above 0.7 is a strong fit. Below 0.4, your trendline is mostly hopeful thinking.
Same pane, the Forecast section. Forward extends the line past your last data point — type a number like 3 for three more periods. Backward extends it before your first point. Useful for showing implied historical baseline. Both extensions are still part of the same trendline math, so they assume the pattern continues.
You can add multiple trendlines to the same series — linear plus polynomial, say, for comparison. Right-click the series each time and pick Add Trendline; the second one stacks on top of the first. To delete one, click it once and press Delete. For deeper background on the math behind these fits, the excel linear regression guide walks through SLOPE, INTERCEPT, and LINEST. If you arrived from a how to add a trendline in excel search, that's the dedicated walkthrough with screenshots.
Equation: y = mx + b
When to use: Steady growth or steady decline. Monthly sales, weight tracking, headcount over time. The classic best-fit. Excel's default for a reason — fits most business data well enough.
Limits: Bad fit for data that curves or saturates.
Equation: y = c·ln(x) + b
When to use: Sharp early growth that levels off. New product adoption, viral signup curves, the early period of any market that saturates.
Limits: Requires positive x values.
Equation: y = a·x² + b·x + c (and higher orders)
When to use: Data with one or more bumps. Quarterly seasonal patterns, sine-like cycles. Set Order from 2 to 6 — higher order means more bends.
Warning: Higher orders overfit noise. Stop at Order 3 for most cases.
Formula: Mean of last N periods.
When to use: Noisy daily or weekly data where you want the underlying signal. Set Period to 3 for short-term smoothing, 6-12 for long-term.
Limits: Can't forecast forward — it stops at your last data point.
Equation: y = c·e^(bx)
When to use: Compounding growth. Compound interest, unrestricted population growth, early-stage viral spread. Curves upward faster and faster.
Limits: Requires positive y values.
This one trips people up because Excel doesn't have an "add average line" button. The trick is to add a helper column filled with the average — then plot that column as a brand-new series. Once you see it once, it takes 90 seconds.
Suppose your data sits in B2:B13 (twelve months of sales). In an empty column — say D2:D13 — type this formula in D2: =AVERAGE($B$2:$B$13). The dollar signs lock the range. Copy that down to D13. Every cell in D now shows the same number — the average. That's intentional. It gives you a flat horizontal line when plotted.
Right-click the chart → Select Data → Add. In the Edit Series dialog: Series name = "Average", Series values = D2:D13. Hit OK. Excel adds a new line right across the middle of the chart at the average value.
Same method, different formula. Type your goal value (say 50000) into D2, then either copy it down or use =50000. Or pull it from a cell elsewhere — =$F$1 where F1 holds your target. Now when somebody changes the target in F1, the goal line on the chart moves automatically.
You could draw a horizontal line shape across the chart. People do. But that line doesn't move when the data changes, doesn't update when the chart resizes, and isn't part of the chart object — copy the chart somewhere else and the line gets left behind. A real series via the helper column travels with the chart everywhere it goes.
Right-click the new series → Format Data Series. Pick Line: Solid line, color = bold red or dashed gray (so it reads as different from your data). Set Marker: None so it doesn't show data point dots. Width = 1.5pt for visibility without dominating. You now have a chart with a real, live-updating average line. The same idea covers Year-To-Date averages, rolling-12-month averages, and quartile lines.
A reference line marks a specific event — the day a product launched, the threshold above which a customer is profitable, the regulatory limit you can't exceed. Average lines stretch across the whole chart. Reference lines mark one specific x or y value. Different jobs, different methods.
Excel doesn't have a built-in "add vertical line" button on column or line charts. The workaround: overlay an X-Y Scatter series that contains exactly two points, both at the same x value, one at the bottom and one at the top of your y-axis.
Set up a tiny two-row helper table somewhere off to the side. Two columns — X and Y. Row 1: X = 6 (the sixth month, where you want the line), Y = 0. Row 2: X = 6, Y = 100000 (or whatever your max y-axis value is). Now right-click your chart → Select Data → Add. Name = "Launch date". For Series values use the Y column.
After it lands, right-click that new series → Change Series Chart Type → set just this one series to Scatter with Straight Lines. Then right-click the new scatter series → Select Data → Edit → and add the X column to the X values box. A clean vertical line appears at month 6.
Easier — it's basically the average line method with a hardcoded value instead of AVERAGE. Helper column = your threshold (say, the 80% mark, or the upper control limit). Plot as a new series. Format the line in a contrasting color. Done.
Three big use cases. Event markers — "product launch was March 15." Thresholds — quality control upper/lower limits, the line above which alerts fire. Targets — quarterly quota, daily call goal. Reference lines anchor the rest of the chart in business context.
A vertical line without a label just looks like Excel got confused. Add a text box (Insert → Text Box) right next to the line: "Product launch — Mar 15." Group the text box with the chart (Ctrl-click both, right-click → Group) so it travels with the chart. Or use a data label on the top point of the scatter line with custom text. Either way, never ship a reference line with no label.
For step-by-step screenshots of the original technique applied to line charts specifically, the how to add a line in excel graph walkthrough covers it in detail.
This is the trick that makes a chart feel professional. Monthly revenue as columns, with a line over the top showing cumulative running total. Or daily calls as bars with a line for service level percentage. One picture, two metrics, two visual styles. Excel calls this a Combo chart.
Select your data, including both series. Go to Insert → Recommended Charts → All Charts → Combo. The dialog at the bottom shows each series with a dropdown: Clustered Column, Line, Area, Stacked Column, and so on. Set your primary metric to Clustered Column. Set your secondary metric to Line. Click OK. Done.
Already have a chart? Right-click any series → Change Series Chart Type. Same dialog opens. Change only the series you want as a line to Line, leave the others alone. The chart redraws instantly.
If your two series are on totally different scales — revenue in dollars and conversion rate in percent — they need separate y-axes or the smaller one squashes flat. In the Combo dialog, tick the Secondary Axis checkbox next to the series you want on its own axis. That series now gets a right-hand y-axis with its own scale. The chart still shows both metrics overlapping on the same time axis.
Sales by month (bars) + running total (line). Daily call volume (bars) + SLA percentage on secondary axis (line). New customers (bars) + cumulative customers (line). Quarterly revenue (bars) + year-over-year growth percentage (line). Each of these takes about two minutes to build once you've done it once.
Two things. First, picking Line for both series — that's just a regular two-line chart, not a combo. Second, forgetting the secondary axis and ending up with one series visually flatlined at zero. Always check both axes after building. If a line looks dead, it probably needs the secondary axis toggled on.
Lay out the data in three columns: time periods (months), Series 1 values (sales), Series 2 values (target or running total). Headers in row 1.
Select all three columns including headers. Insert → Recommended Charts → All Charts tab → Combo. The dialog at the bottom lists each series with a chart type dropdown.
Set Series 1 (sales) to Clustered Column. Set Series 2 (target or running total) to Line. Click each dropdown individually — don't accept the default.
If the two series are on different scales (dollars vs percent, or millions vs thousands), tick Secondary Axis next to the line series. Right-hand y-axis appears.
Click OK to build. Add chart title (Chart Design → Add Chart Element → Chart Title). Format the line color to contrast with the bars. Add axis titles on both axes.
These are the small visual lines you've seen on line charts in professional reports — thin vertical lines connecting each data point down to the category axis, or fat bars showing the gap between two series. Excel calls them Drop Lines and Up-Down Bars. They're not separate series. They're chart elements you toggle on.
Click the chart. Chart Design → Add Chart Element → Lines → Drop Lines. Excel drops a thin vertical line from every data point straight down to the x-axis. That's it. Two clicks.
Drop lines work on line charts and area charts. They help when the values vary wildly and your eye loses track of which point sits over which x-axis label. The lines re-anchor every point to its category.
If you have two series — open and close, high and low, forecast and actual — High-Low Lines connect each pair of points with a thin vertical line. Add Chart Element → Lines → High-Low Lines. Each x category now shows a vertical line marking the range between the two values. Use this when you want to show variability or uncertainty at every point.
Same family. With two series on a chart, Add Chart Element → Up/Down Bars → Up/Down Bars turns the gap between them into white bars (when series 2 is higher) and black bars (when series 1 is higher). Classic stock chart use: open vs close. Black bar = down day. White bar = up day. Excel even matches Wall Street convention by default.
Help: when there's a lot of data and the x-axis labels are crowded — drop lines make each value's category clear. Hurt: when the chart already has gridlines, since drop lines plus gridlines plus markers add up to visual noise. If you turn on drop lines, often you should turn off the vertical gridlines too. Strip everything else back so the drop lines do their job clearly.
Click any drop line once — Excel selects all of them as a group. Right-click → Format Drop Lines. Standard line formatting pane appears: color, width, dash style. A pale gray 0.75pt line is the unobtrusive default. Anything darker or thicker fights with your data.
Two series on the same chart with wildly different scales is a common problem. Revenue in millions, conversion rate as percent. Calls in thousands, average handle time in seconds. Put them both on one axis and one of them goes flat at the bottom. The secondary axis fixes this in two clicks.
Easiest: right-click the series that's getting squashed → Format Data Series → under Series Options, tick Secondary Axis. A second y-axis appears on the right side of the chart with its own scale. The squashed series jumps up to visible range. Alternative: in the Combo chart dialog (Change Chart Type → Combo), tick the Secondary Axis box next to the series in the list.
Right-click the new right-side axis → Format Axis. Same settings as the left axis. Set the minimum (often 0), the maximum (a clean round number above your data), the number format (percentage, currency, plain number). Add an axis title via Chart Design → Add Chart Element → Axis Title → Secondary Vertical. Label it clearly so readers know which line corresponds to which axis.
The pro move: color the axis numbers to match the series. Right-click the secondary axis → Format Axis → Font Color → match the line's color. Now readers instantly know which axis goes with which series. Do the same on the primary axis. Two color-coded axes, two lines, no ambiguity.
If both series are the same kind of measure (both dollars, both counts) and they're roughly the same scale, don't add a second axis. It's visually misleading — readers assume the closer the two lines get, the more they agree, but with two different scales "close" means nothing. Reserve the secondary axis for when the units genuinely differ.
Most of this works the same across versions. A few menu paths differ, and Excel 365 has a couple of shortcuts that older versions don't.
Excel 365 and 2019 both use the right-side Format pane that opens when you right-click → Format Data Series. Excel 2010 and earlier used a floating dialog box instead. Same options, different visual container. The settings inside are identical.
Excel 365 has Insert → Recommended Charts, which previews several chart types based on your selected data. Excel 2013 onward has this too. Excel 2010 doesn't — you pick the chart type manually from the gallery.
For trendlines specifically, Excel 365 and 2016 have a Forecast Sheet feature (Data tab → Forecast Sheet). It builds a separate chart with built-in trendline, confidence interval bands, and seasonality detection — much smarter than the manual trendline approach. Earlier versions don't have it.
Click a chart in Excel 365, and a green plus icon appears at the top-right corner. Click it for a quick checklist of chart elements — including Trendline, Drop Lines, and Up/Down Bars. Faster than going through the Chart Design tab. Excel 2013+ has this; earlier versions don't.
Excel 365 lets you rename a series in place: click the legend twice slowly, type the new name. Older versions require going through Select Data → Edit. Both still work in 365 — just two paths to the same result. For a deeper dive on naming see how to change series name in excel.
Right-click the chart → Select Data → Add. Type a name in Series name, click in the Series values box, then select the cells with the new numbers. Click OK twice. The new line appears on the chart immediately. This works for line charts, column charts, and most chart types in Excel 365, 2019, and 2016.
Right-click directly on the data series (the line or column on the chart) — not on the chart background. Choose Add Trendline. The Format Trendline pane opens on the right. Pick Linear, Logarithmic, Polynomial, Moving Average, Exponential, or Power. Tick Display Equation and Display R-squared at the bottom if you want the math visible on the chart.
Excel has no "add average line" button — you build it with a helper column. In an empty column, enter =AVERAGE($B$2:$B$13) using your data range. Copy down so every row has the same value. Then right-click the chart → Select Data → Add → point Series values to the helper column. A flat horizontal line appears at the average.
Create a tiny two-row helper table: X and Y. Both X values equal the date or category number where you want the line. The Y values span from your axis minimum (typically 0) to your axis maximum. Add this as a new series, then right-click it → Change Series Chart Type → set to Scatter with Straight Lines. Re-edit to assign the X column to X values. A clean vertical line appears at the chosen x-value.
A trendline (linear, polynomial, exponential, etc.) is a single math line fit through all your data using regression. A moving average smooths noisy data by averaging the last N periods at each point — it follows the actual data shape more closely but can't forecast forward past your last data point. Use trendline for projection. Use moving average for smoothing.
Three usual reasons. First, the values are on a different scale and the line is hidden along the zero baseline — add a secondary axis to fix it. Second, the series values box has wrong range references — re-open Select Data → Edit and check the range. Third, the new series got the same color as an existing one and looks like one combined line — right-click the new series → Format Data Series → change the line color.
Use the average line method with your goal value instead of AVERAGE. In a helper column type your target number (or =$F$1 where F1 holds the target). Copy that constant down to match your data range. Right-click chart → Select Data → Add → name it "Goal" → point Series values to the helper column. A flat line appears at your target value.
Yes. Select your data, then Insert → Recommended Charts → All Charts → Combo. The dialog at the bottom lists every series with a chart-type dropdown. Set one series to Clustered Column and the other to Line. Tick Secondary Axis on the line series if the scales differ. Click OK. You now have a combo chart with bars and a line on the same canvas.