Clear line charts in Power BI with Line Plume

At a glance

• What the visual does. Line Plume draws lines and areas, like a temperature log pinned to the wall: one line per series, rising and falling over time. Dates are spaced according to their real distance (a two-month gap shows). You can add comments pinned to points, a moving average, a trend extended into the future, targets and events.
• When to use it:
  • track a change over time (monthly revenue, daily visits, weekly stock);
  • compare several series over the same period (sales channels, regions, actual and budget);
  • compare two quantities on different scales (an amount in euros and a rate in %) thanks to the secondary Y axis;
  • explain a peak or a dip right on the line, or show a forecast.
• When to use something else: to compare categories with no notion of time (top 10 products), use Bar Plume instead. For bars and lines in the same chart, Line Plume is not the right fit: it only draws lines and areas.
• By the end, you will know how to:
  • prepare a date table and a measure, and choose between a continuous date axis and a categorical axis;
  • plot several lines, with several measures or with the Legend (series) field;
  • add a secondary Y axis and adjust each series separately with the Per-series settings card;
  • annotate a point in three ways;
  • add a moving average, a trend with a forecast and a dashed future part.
• What you need:
  • Power BI Desktop (recent version);
  • the Line Plume visual installed (see the shared basics, "Installing a Plume visual");
  • a column of dates (or months, years, categories) and at least one numeric measure.

The data you need

The expected shape

The visual reads one row per X axis value (one row per month, for example), and one row per X axis value and per series when you use the Legend (series) field.

• The X axis is a column (a column of your table, see the glossary): a date, a number (a year written as 2024) or text ("Q1 2025").
• The series (optional) is also a column: each distinct value (Store, Online…) gives one line.
• The values are measures (a DAX calculation, see the glossary, that adapts to filters, for example "sum of amounts"). The visual asks for a measure rather than a raw column because the calculation must be redone for each month and each series.

The sample dataset

A home goods retailer tracks its sales from January to June 2025, across two channels (fictitious data). One row per month and per channel.

Month	Channel	Amount	Margin
2025-01-01	Store	42000	15100
2025-01-01	Online	18500	7200
2025-02-01	Store	38400	13600
2025-02-01	Online	19900	7900
2025-03-01	Store	45200	16500
2025-03-01	Online	24300	9800
2025-04-01	Store	40100	14200
2025-04-01	Online	22800	9000
2025-05-01	Store	47600	17400
2025-05-01	Online	27500	11300
2025-06-01	Store	51300	18900
2025-06-01	Online	31200	12900

To create this table without an Excel file: Modeling › New table, then paste:

Sales =
DATATABLE (
    "Month", DATETIME,
    "Channel", STRING,
    "Amount", DOUBLE,
    "Margin", DOUBLE,
    {
        { "2025-01-01", "Store", 42000, 15100 },
        { "2025-01-01", "Online", 18500, 7200 },
        { "2025-02-01", "Store", 38400, 13600 },
        { "2025-02-01", "Online", 19900, 7900 },
        { "2025-03-01", "Store", 45200, 16500 },
        { "2025-03-01", "Online", 24300, 9800 },
        { "2025-04-01", "Store", 40100, 14200 },
        { "2025-04-01", "Online", 22800, 9000 },
        { "2025-05-01", "Store", 47600, 17400 },
        { "2025-05-01", "Online", 27500, 11300 },
        { "2025-06-01", "Store", 51300, 18900 },
        { "2025-06-01", "Online", 31200, 12900 }
    }
)

The measures to create

Select the Sales table, then Modeling › New measure, once per measure:

// Revenue: adds up the Amount column
// for the month and channel of each point on the line.
Revenue = SUM ( Sales[Amount] )

// Margin rate: margin divided by revenue.
// DIVIDE avoids the divide-by-zero error (returns blank instead).
// Give it the Percentage format (Measure tools › Format).
Margin Rate = DIVIDE ( SUM ( Sales[Margin] ), [Revenue] )

// Two "filtered" measures: useful to plot several lines
// WITHOUT the Legend field (see section 3).
// CALCULATE recomputes [Revenue] keeping only the given channel.
Store Revenue = CALCULATE ( [Revenue], Sales[Channel] = "Store" )
Online Revenue = CALCULATE ( [Revenue], Sales[Channel] = "Online" )

// A fixed target, for the how-to guides (horizontal line, threshold).
Target = 45000

Data preparation pitfalls

• The Month column must be of type Date (or Date/Time). A text value such as "Jan 2025" would be treated as a category: evenly spaced points, and possibly alphabetical sorting.
• Use the field itself, not its date hierarchy. Power BI often creates a date hierarchy (Year › Quarter › Month › Day, see the glossary). If you leave it, the visual only receives the years. In the X axis well, click the arrow next to the field and choose its name (Month) instead of Date Hierarchy.
• A single granularity (the level of detail, see the glossary): set every date to the 1st of the month if you track months. Dates down to the day would give one point per day.
• Blank values: a month with no sales returns a blank value. By default the line breaks; you choose this behavior in Lines › Missing values.
• Volume: the visual loads up to 30,000 X axis values per batch, then automatically fetches the rest up to 100,000. Beyond that, a warning icon tells you that only the first rows are loaded. Up to 60 series.

Step by step: your first Line Plume chart in 10 minutes

You start from the Sales table and the Revenue and Margin Rate measures from the "The data you need" section.

1. In the Visualizations pane, click the Line Plume icon. An empty frame appears on the page, with the visual's welcome screen.

2. In the Data pane, drag Sales[Month] into the X axis well. If Power BI shows Date Hierarchy, click the arrow on the field and choose Month.

3. Drag the Revenue measure into Y axis values. A line appears: total revenue per month, from January to June 2025.

4. Drag Sales[Channel] into Legend (series). The line splits in two: a Store line and an Online line, each in its own color, with a legend at the top.

5. In the Format pane, X axis card, Date format setting: type MMM yyyy. The axis labels become "Jan 2025", "Feb 2025"…

6. Lines card, Stroke group, Shape: choose Smooth. The corners of the lines become rounded, without overshooting the real values.

7. Still in Lines, Markers group, Markers: choose Last point. A dot marks the last value of each line.

8. Y axis card, Suffix (e.g. €): type € (with a space before it). The Y axis ticks now end with €.

9. Title card, Title: type Monthly revenue by channel.

10. Hover over the chart. A vertical guide follows the mouse and a single tooltip gives the revenue of both channels for the hovered month.

Expected result: two smooth lines, Store above Online, both rising until June 2025, with a readable date axis and amounts in euros. Everything you set is free: no watermark.

Troubleshooting

What you see	Likely cause	Fix
The X axis only shows years	The date hierarchy was dropped instead of the field	In the X axis well, field arrow › choose Month (the field itself)
You can't add a second measure to Y axis values	A field is in Legend (series): only one measure per axis	Remove the Legend to plot several measures, or put the second one in Secondary Y axis values
The Secondary Y axis card is nowhere to be found	No measure in Secondary Y axis values	Drag a measure into it
Date format or Long labels doesn't appear	The first only shows on a date axis, the second only on a categorical axis	Check the column type and X axis › Axis type
The same annotation on every line	The annotation measure ignores the series	Restrict it with SELECTEDVALUE (see the Annotations how-to guide)
An annotation is missing; message "Annotation ignored (series or x not found)" at the bottom, in edit mode	Unknown series name, unreadable date, or x outside the axis range	Fix the line; write dates as 2025-03-15, which is always understood
03/15/2025 misread in a list	Day/month order follows the number format locale	Use the 2025-03-15 format
A Lines card setting has no effect on one series	The series has its own value in Per-series settings, which wins	Set the option back to Same as the Lines card for that series
No forecast	Forecast periods is 0, or the series has fewer than 3 points (Holt-Winters without two full seasons falls back to Holt)	Set Forecast periods, add more history
Points disappear on a logarithmic scale	Zero or negative values are ignored on a log scale	Switch back to Linear or filter out those values
Warning icon: only the first rows are loaded	More than 100,000 values on the X axis	Reduce the granularity (months instead of days) or filter
"Plume Visuals · Premium preview" watermark	A ★ feature is used without a valid key	Paste your key, or turn off the ★ feature (see the "Premium ★ features" section)

Key takeaways

• Put a column in X axis (the date field itself, not the hierarchy) and measures in the values; the continuous date axis respects the real distance between dates.
• Several lines: several measures without a Legend, or one measure and the Legend (series) field, never both.
• The secondary Y axis compares two quantities on different scales; the Per-series settings card handles exceptions (All series, then one series: the series wins).
• An annotation is pinned to a point (x, series): Annotate button, x | series | text list or text measure.
• The Analytics pane adds a moving average, a trend with a forecast and reference lines; the dashed future part separates actuals from the forecast on a single line.

Learn more

• Line Plume: 8 how-to guides (dual axis, forecast, moving average…): recipes for everyday needs.
• Line Plume: every field and setting explained: each field well and each setting.
• Annotating a line: comments pinned to points: annotations in detail.
• Getting started with Plume visuals: installation, license, styles and settings shared by all visuals.
• The visual's page: Line Plume. A question? Support.