Analytics and measurement
Year-over-Year Change Calculator
Compare the same metric across two years for as many metrics as you like, and see the change in numbers and in percent.
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How to use
- Name the two periods if you want labels.
- Add a row for each metric with this year's value and last year's.
- Read the absolute and percentage change for each row.
- Check the notes for zero baselines and negative values.
What it checks and how it works
Change = (this year - last year) / |last year|, and the absolute change is this year minus last year. Comparing the same stretch of the calendar in two years lines up the seasons, as the Corporate Finance Institute describes for year-over-year analysis.
It does not remove one-off events, a different number of trading days, a change in how the metric is measured or a change in what the business sells. When last year's value is zero the percentage is undefined and the row says so instead of showing a huge or infinite number. Percentages on a small base can look dramatic; read them next to the absolute change.
Sources
- Corporate Finance Institute: YoY (Year over Year) opened 29 Oct 2026
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Questions
About this tool
Many businesses have seasons, so month-on-month change mixes growth with the calendar. The same period a year earlier removes most of that effect.
A percentage change from zero is undefined, so the tool shows the absolute change and no percentage. Report the figure itself instead.
No. Year-over-year compares two points. CAGR smooths the growth between a start and an end point over several years into one annual rate; use the CAGR tool for that.
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