LOGEST Function (LibreOffice Calc)

Math Advanced LibreOffice Calc Introduced in LibreOffice 3.0
regression exponential statistics data-analysis modeling forecasting

The LOGEST function in LibreOffice Calc performs exponential regression and returns statistics describing the best-fit exponential curve. This guide explains syntax, array behavior, regression output, examples, errors, and best practices.

Compatibility

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What the LOGEST Function Does â–¾

  • Fits data to an exponential curve
  • Returns growth factor(s), intercept, and full regression statistics
  • Supports multi-variable exponential regression
  • Works as an array function
  • Ideal for forecasting, growth modeling, and scientific analysis
  • Works across sheets

LOGEST is the exponential counterpart to LINEST.

Syntax â–¾

LOGEST(known_y; known_x; const; stats)

Where:

  • known_y — dependent variable (must be positive)
  • known_x — independent variable(s)
  • const — TRUE = calculate intercept; FALSE = force intercept = 1
  • stats — TRUE = return full regression statistics; FALSE = return only coefficients
LOGEST returns an array.
Older Calc versions require Ctrl+Shift+Enter.
Modern Calc spills automatically.

Output Structure â–¾

When stats = FALSE:

Column 1 Column 2
m (base) b (intercept)

The model is:

y = b * m^x

When stats = TRUE, LOGEST returns a 5-row array, identical in structure to LINEST:

Row Meaning
1 m (base), b (intercept)
2 Standard errors
3 R², Standard error of Y estimate
4 F-statistic, Degrees of freedom
5 Regression sum of squares, Residual sum of squares

Basic Examples â–¾

Simple exponential regression (Y vs X)

=LOGEST(B1:B10; A1:A10)

Regression with intercept forced to 1

=LOGEST(B1:B10; A1:A10; FALSE)

Full regression statistics

=LOGEST(B1:B10; A1:A10; TRUE; TRUE)

Regression across sheets

=LOGEST(Sheet1.B1:B50; Sheet2.A1:A50)

Advanced Examples â–¾

Predict Y using LOGEST coefficients

Base (m):

=INDEX(LOGEST(B1:B10; A1:A10); 1)

Intercept (b):

=INDEX(LOGEST(B1:B10; A1:A10); 1; 2)

Prediction:

=INDEX(LOGEST(B1:B10; A1:A10); 1; 2) * INDEX(LOGEST(B1:B10; A1:A10); 1) ^ X

Use LOGEST inside GROWTH for forecasting

=GROWTH(B1:B10; A1:A10; A11:A20)

Exponential regression ignoring errors

=LOGEST(IF(ISNUMBER(B1:B10); B1:B10); A1:A10)

(Confirm with Ctrl+Shift+Enter in older Calc.)

Exponential regression on visible cells only

Use SUBTOTAL helper column to filter X/Y before passing to LOGEST.

Multi-variable exponential regression

=LOGEST(Y1:Y20; X1:Z20; TRUE; TRUE)

Log-linear transformation (manual equivalent)

=LINEST(LN(B1:B10); A1:A10)

LOGEST automates this transformation.

Requirements and Constraints â–¾

  • All Y values must be positive (because LOGEST uses natural logs internally)
  • X values may be any real numbers
  • Multi-variable regression requires matching row counts

Common Errors and Fixes â–¾

Err:502 — Invalid argument

Occurs when:

  • Y values contain zero or negative numbers
  • X and Y ranges have mismatched lengths
  • Non-numeric text included

Err:504 — Parameter error

Occurs when:

  • Semicolons are incorrect
  • Array dimensions are invalid

LOGEST returns #N/A

Occurs when:

  • Not enough data points
  • Forced intercept creates invalid model
  • Predictors are linearly dependent

R² seems too low or too high

Possible causes:

  • Data is not exponential
  • Outliers distort the curve
  • X values not scaled

Best Practices â–¾

  • Use LOGEST for growth/decay modeling and exponential forecasting
  • Use GROWTH for direct exponential predictions
  • Always inspect R² and residuals
  • Remove or investigate outliers
  • Ensure Y values are strictly positive
  • Use named ranges for cleaner formulas
LOGEST is the key to modeling exponential processes — population growth, decay curves, compounding, and more. Master it, and you unlock a powerful class of predictive analytics.

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