Check forecasting performance across several periods
MAPE can make a small set of forecast errors easier to summarize than reviewing each period separately.
Everyday Tools
Estimate mean absolute percentage error from paired actual and forecast value lists.
Why this page exists
Forecast reviews are easier to summarize when several actual-versus-forecast pairs turn into one average percentage error instead of being checked line by line. This calculator helps visitors estimate mean absolute percentage error, or MAPE, from paired actual and forecast values while handling zero-actual cases clearly.
Interactive tool
Enter your numbers and read the result first, then use the sections below to understand what affects the outcome.
Calculator
Estimate mean absolute percentage error from paired actual and forecast value lists.
Result
Estimated mean absolute percentage error based on the valid paired actual and forecast values entered.
This is a standard MAPE estimate. It assumes the actual and forecast lists line up in the same order, and it skips zero-actual pairs because MAPE is undefined when the actual value is zero.
Planning note
Last updated April 15, 2026. Use this tool to compare scenarios and plan ahead, then confirm important details with the lender, employer, insurer, contractor, or other qualified provider involved in the final decision.
How it works
Enter matching actual values and forecast values as comma-separated lists.
The calculator pairs the values in order and finds the absolute percentage error for each usable pair.
It averages those errors to estimate MAPE and clearly reports any zero-actual or unmatched entries that were skipped.
Understanding your result
This is a standard MAPE estimate. It skips zero-actual pairs because percentage error is undefined when the actual value is zero, so the result stays readable instead of implying a misleading percentage.
Browse more everyday toolsExamples
Example scenarios help turn a quick estimate into a more useful comparison or planning step.
MAPE can make a small set of forecast errors easier to summarize than reviewing each period separately.
The calculator flags zero-actual pairs clearly so they do not distort the average percentage error.
MAPE often fits naturally beside forecast accuracy, mean absolute deviation, and standard-error tools.
FAQ
The calculator finds the absolute percentage error for each usable actual-forecast pair and then averages those percentage errors.
That pair is skipped and reported clearly because MAPE is undefined when the actual value is zero.
Teams can handle weighting, rollups, missing values, and zero-actual cases differently, so the final percentage can vary by method.
Related tools
Use these related tools to compare nearby scenarios, check a second estimate, or keep narrowing down the right decision.
Calculate mean absolute deviation from a comma-separated list of numbers.
Estimate standard error from standard deviation and sample size.
Estimate absolute error and percentage error from an observed value and a reference value.
Calculate standard deviation, variance, and mean from a comma-separated list of numbers.
Estimate the average of a list of numbers from a comma-separated input.