Statistical

TREND Function in Excel

Returns values along a linear trend.

Syntax

  • =TREND(known_y's, [known_x's], [new_x's], [const])

Arguments

  • known_y's (required): Known y values
  • known_x's (optional): Known x values
  • new_x's (optional): X values for predictions
  • const (optional): TRUE to calculate intercept

Examples

  • =TREND(B1:B10, A1:A10, A11:A15) - Predict linear trend - Result: Predicted values

Excel TREND function documentation

  • TREND returns y values along a linear trend based on known data — array formula legacy, dynamic in 365.
  • Syntax: =TREND(known_y's, [known_x's], [new_x's]).
  • Fit straight line to historical points and project multiple future periods at once.
  • Related: [FORECAST.LINEAR](/functions/forecast-linear/), [GROWTH](/functions/growth/), [LINEST](/functions/lin-est/).

TREND syntax

  • known_y's required — dependent values.
  • known_x's optional — default 1,2,3,... n.
  • new_x's points to predict — omit for fitted values on known x.
  • In 365 spills results; legacy required array entry on some builds.

Step-by-step: forecast three future periods

  • Step 1 — Period 1..10 in A, values in B.
  • Step 2 — new_x = {11;12;13} or cell range.
  • Step 3 — =TREND(B2:B11, A2:A11, A12:A14).
  • Step 4 — Chart actuals + TREND line.
  • Step 5 — Validate linear assumption — curvature needs GROWTH or nonlinear model.

TREND vs FORECAST.LINEAR vs chart trendline

  • TREND — many points formula-driven.
  • FORECAST.LINEAR — single x.
  • Chart trendline — visual; equation on chart.
  • Statistical category hub linked from function page.

Worked examples to copy

  • Fitted values: =TREND(B2:B10, A2:A10).
  • Future only: =TREND(B2:B10, A2:A10, A11:A15).
  • Default x: =TREND(y_values) only.
  • With IFERROR wrap for short series.

People also ask

  • TREND #REF!? — new_x wrong size or mismatch.
  • TREND vs LINEAR regression? — TREND uses least squares linear fit.
  • TREND seasonal? — Poor fit — seasonally adjust first.
  • TREND Google Sheets? — Similar TREND(known_y, known_x, new_x).

Common errors

  • Arrays must be compatible sizes

Use cases

  • Linear forecasting
  • Trend projection
  • Data extrapolation

Frequently asked questions

  • What is TREND function in Excel? TREND calculates predicted Y values along a linear trend line. It performs linear regression internally and returns fitted/predicted values. Use it to forecast future values, fill in missing data points, or smooth noisy data along a linear trend.
  • How do I use TREND for forecasting? Use =TREND(known_y, known_x, new_x). Example: With sales of 100, 150, 200 for months 1-3, =TREND({100,150,200}, {1,2,3}, {4,5,6}) predicts months 4-6. TREND fits a line and extrapolates to new X values.
  • What's the difference between TREND and FORECAST.LINEAR? FORECAST.LINEAR predicts a single Y value for one X value. TREND can predict multiple values at once and can handle multiple X variables (multiple regression). Use FORECAST.LINEAR for simple single predictions; use TREND for arrays or multiple regression.

Editorial review

  • Reviewed by Excel.Directory Editorial Team. Updated May 2026.

When to use TREND

  • Linear forecasting — common Statistical scenario for TREND.
  • Trend projection — common Statistical scenario for TREND.
  • Data extrapolation — common Statistical scenario for TREND.

TREND in the Statistical category

  • Browse all Statistical functions at /categories/statistical/ for related formulas.
  • TREND syntax: =TREND(known_y's, [known_x's], [new_x's], [const])
  • known_y's (required): Known y values
  • known_x's (optional): Known x values
  • new_x's (optional): X values for predictions
  • const (optional): TRUE to calculate intercept
  • Confirm TREND arguments match the syntax shown above before filling down.
  • Lock table and range references with $ when copying formulas across rows or sheets.

Formula checklist before you copy down

  • Confirm TREND arguments match the syntax shown above before filling down.
  • Lock table and range references with $ when copying formulas across rows or sheets.
  • If results look wrong, check for text stored as numbers and invisible spaces with TRIM.
  • Spot-check three known input rows manually against expected output.

Related Excel functions

  • LINEST (/functions/linest/): Returns the parameters of a linear trend using least squares method.
  • GROWTH (/functions/growth/): Returns values along an exponential trend.
  • FORECAST.LINEAR (/functions/forecast-linear/): Calculates a future value using linear regression.

Errors to watch for

  • Arrays must be compatible sizes — review causes on linked error pages in the directory.

Copy-paste audit workflow

  • Enter TREND on three test rows with known expected output documented on a QA tab.
  • Fill down only after absolute references are locked on lookup tables and rate tables.
  • Compare against manual calculation or a calculator for financial and statistical functions.
  • Search this directory for comparison guides when choosing between similar functions in the same category.

TREND worked examples to copy

  • =TREND(B1:B10, A1:A10, A11:A15) — Predict linear trend. Expected result: Predicted values.

TREND reference summary for crawlers and offline review

  • TREND belongs to the Statistical category in Excel. Returns values along a linear trend.
  • Full syntax: =TREND(known_y's, [known_x's], [new_x's], [const]). Open /functions/trend/ for parameters, FAQs, and related pages.
  • Common mistakes: Arrays must be compatible sizes
  • Pair this function with comparison guides when another Excel formula might fit the same task better.
  • Review fix-excel-formula-errors when unexpected errors appear after upgrading Excel or sharing across locales.