Free Year-over-Year Growth Calculator
Year over year growth is the current value minus the value from the same period last year, divided by last year's value, times 100. Enter both numbers and this free calculator returns the YoY percentage, the absolute change and the growth factor, worked out in your browser.
Calculate Your Growth Rate
Use matching periods, for example Q2 this year versus Q2 last year.
Enter the two period values above to calculate the result.
Year-over-year growth result
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How to Use the Year-over-Year Growth Calculator
Year-over-year growth compares a metric with the same period one year earlier. Marketers use it to reduce the effect of seasonality and answer a simple question: is this part of the business growing, declining or holding steady compared with last year?
What YoY growth tells marketers
YoY growth expresses the change as a percentage of the prior-period value. It is useful for evaluating revenue, leads, conversions, traffic, subscribers and other non-negative marketing metrics while keeping seasonal periods comparable.
1. Choose matching periods
Enter a prior value and a current value that cover equivalent time spans. Compare January with January, Q2 with Q2 or one complete year with the previous complete year. Mixing a full month with a partial month produces a misleading result.
2. Use a consistent metric definition
Make sure both values come from the same analytics source and use the same filters. If “leads” included trial signups last year but excludes them this year, the percentage reflects a tracking change rather than true performance.
3. Read percentage and absolute change together
The YoY percentage shows the relative movement, while absolute change shows the actual units gained or lost. A 100% increase from 10 to 20 leads is mathematically impressive but may have less business impact than a 10% increase from 10,000 to 11,000.
4. Add context before reporting
Use the result as a starting point, not the complete explanation. Note major campaign launches, tracking changes, price increases, market conditions and unusual seasonal events. If the prior value is zero, report the absolute increase instead of a percentage because YoY growth is undefined.
YoY Growth Formula
| Prior year | Current year | Absolute change | YoY growth |
|---|---|---|---|
| 1,250 | 1,565 | +315 | +25.2% |
Year over year growth percentage vs. growth factor
The calculator shows the same comparison three ways. The YoY percentage is the relative change (+25.2% above). The growth factor is current divided by prior (1.25×), and "current vs. prior" expresses that factor as a percentage (125.2%). A factor below 1 always means a decline.
Year Over Year Growth Calculator in Excel
To repeat this calculation across many rows, use the same formula in Excel or Google Sheets. With the prior-year value in column A and the current-year value in column B:
Format column C as a percentage and fill the formula down. Wrap it as =IF(A2=0,"n/a",(B2-A2)/A2) so a zero prior value returns "n/a" instead of a division error, which matches how this calculator handles a zero baseline.
Year over year sales and revenue growth
Sales and revenue are the most common YoY comparisons. Compare the same fiscal period in both years, use the same currency and the same definition of revenue (gross or net, with or without refunds), and note any price change, because a price increase can raise revenue growth while unit sales stay flat.
Growth across multiple years
YoY growth compares two periods only. When you need an average rate across three or five years, calculate each year's YoY change separately or use the compound annual growth rate, (final ÷ starting)^(1 ÷ years) − 1, which smooths uneven years into one yearly figure.
Year-over-Year Growth FAQs
What is year over year growth?
Year over year (YoY) growth is the percentage change in a metric compared with the same period one year earlier, such as March this year against March last year. Comparing matching periods removes most seasonal swings from the result.
How do you calculate year over year growth?
Subtract the prior-period value from the current-period value, divide the difference by the prior-period value, and multiply by 100. For example, (1,565 minus 1,250) divided by 1,250 times 100 gives 25.2% growth.
How do I calculate year over year growth in Excel?
Put last year's value in A2 and this year's value in B2, then enter =(B2-A2)/A2 in C2 and format C2 as a percentage. Copy the formula down the column to calculate YoY growth for every row.
What does negative YoY growth mean?
A negative result means the current value is lower than the comparable value from the prior year. The size of the percentage shows the relative decline.
Can I calculate YoY growth when the prior value is zero?
No meaningful percentage can be calculated from a zero baseline because division by zero is undefined. Report the absolute change and explain that the metric started from zero.
How do I calculate growth over multiple years?
This calculator compares two periods. For an average yearly rate across several years, use the compound annual growth rate: divide the final value by the starting value, raise the result to the power of 1 divided by the number of years, then subtract 1.
What metrics can I compare with a YoY growth calculator?
You can compare any non-negative metric measured the same way in both periods, such as sales, revenue, leads, conversions, organic traffic, ad spend, email subscribers or marketing-qualified opportunities.
Is the data entered into this calculator stored?
No. This calculator runs locally in your browser. The values are not transmitted to zPlatform or stored by the tool.