Week-Over-Week Calculator — WoW % Change
Enter this week's value and last week's value for any metric — revenue, users, orders, conversions or any KPI — to instantly see the week-over-week percentage change and absolute difference.
Increase of 200 (+20 %)
- 1
Absolute change
1,200 − 1,000 = 200 - 2
WoW % change
200 ÷ |1,000| × 100 = 20The denominator uses |previous| so the sign is correct even for negative baselines.
How does this calculator work?
WoW % change = (current − previous) ÷ |previous| × 100. Positive means growth, negative means decline. The denominator uses the absolute value so sign is correct even for negative baselines. Enter this week's and last week's values; the previous value cannot be zero because that makes percentage change undefined.
Formula
How this is calculated
Week-over-week (WoW) change compares a metric from one week to the equivalent figure from the prior week, expressed as a percentage. The formula is (current − previous) ÷ |previous| × 100 — dividing by the absolute value of the previous figure ensures the result has the correct sign even when previous values are negative (for example, a loss narrowing from −$100 to −$50 is a 50% improvement, not −50%).
The absolute change (current − previous) tells you the raw magnitude of the shift, while the percentage change normalises it so you can compare metrics of different scales fairly. A jump from 10 to 12 and a jump from 1,000 to 1,200 are both 20% WoW increases, even though the absolute differences are very different.
When the previous value is exactly zero the percentage change is mathematically undefined (division by zero), and the calculator shows a warning. For very small previous values the percentage can be very large without reflecting a meaningful change — in those cases the absolute change is the more useful figure.
Frequently asked questions
WoW change compares a metric in a given week to the same metric in the preceding week, expressed as a percentage. It is the most common short-term growth indicator in business reporting — the percentage form lets you compare different-sized metrics fairly without depending on their absolute scale.
Using the absolute value prevents sign errors when the previous figure is negative. If revenue went from −$100 (a loss) to −$50, the improvement is $50 and $50 ÷ $100 = +50%, which is correct. Without the absolute value you would get −50%, which has the wrong sign.
WoW compares the same 7-day period to the immediately prior 7-day period. MoM compares calendar months (28–31 days). WoW reacts faster to short-term changes but is more sensitive to weekday patterns and holiday effects; MoM smooths those out at the cost of slower feedback.
Also known as
TG we-Calculate Editorial Team. (2026). Week-Over-Week Calculator — WoW % Change [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/week-over-week-calculator
TG we-Calculate Editorial Team. "Week-Over-Week Calculator — WoW % Change." TG we-Calculate. 2026. https://we-calculate.com/calculator/week-over-week-calculator.
TG we-Calculate Editorial Team, "Week-Over-Week Calculator — WoW % Change," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/week-over-week-calculator
@misc{wecalculate_week_over_week_calculator, title = {Week-Over-Week Calculator — WoW % Change}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/week-over-week-calculator}}, year = {2026}, note = {TG we-Calculate} }
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