Calculate comp sales percentage from recent and previous revenue, or find either period’s revenue when the other values are known.
Comp Sales Formula
The comp sales calculator uses same-store or comparable sales change to relate revenue in a recent period to a positive previous-period baseline. Use the same eligible cohort and comparable period lengths; the calculator does not determine store eligibility or normalize the supplied totals. USD inputs accept cents, inferred revenue rounds to the nearest cent, and percentage results round to six decimal places.
- CS = comp sales percentage
- CR = revenue generated in the most recent period
- PR = revenue generated in the previous period
To solve for the most recent period revenue, the calculator rearranges the formula:
To solve for the previous period revenue, the calculator uses:
- Calculate comp sales: Choose Comp sales percentage, then enter recent period revenue and positive previous period revenue.
- Calculate recent revenue: Choose Recent period revenue, then enter positive previous period revenue and comp sales percentage (at least −100%).
- Calculate previous revenue: Choose Previous period revenue, then enter positive recent revenue and a comp sales percentage greater than −100%.
Comp Sales Result Interpretation
Comp sales show the percentage change between two comparable periods. Positive values mean sales increased. Negative values mean sales declined.
| Comp Sales Result | Meaning | Simple Example |
|---|---|---|
| +10% | Recent revenue is 10% higher than in the previous period. | $100,000 became $110,000 |
| 0% | Revenue stayed the same. | $100,000 stayed $100,000 |
| -8% | Recent revenue is 8% lower than in the previous period. | $100,000 became $92,000 |
Comparable Period Examples
| Comparison Type | Recent Period | Previous Period |
|---|---|---|
| Monthly comp sales | March 2026 | March 2025 |
| Quarterly comp sales | Q2 2026 | Q2 2025 |
| Weekly comp sales | Week 20 this year | Week 20 last year |
Example
Example 1: Calculate comp sales
You have $125,000 in recent period revenue and $100,000 in previous period revenue.
The comp sales result is 25%.
Example 2: Calculate recent period revenue
You have $80,000 in previous period revenue and comp sales of -5%.
The recent period revenue is $76,000.
FAQ
What does comp sales mean?
Comp sales means comparable sales. It measures revenue growth or decline between two comparable periods, usually using the same store, same location, same business unit, or same set of stores. This helps separate actual sales performance from growth caused by opening new locations or adding new sales channels.
Can comp sales be negative?
Yes. Negative comp sales mean the recent period revenue was lower than the previous comparable period. For example, if revenue falls from $200,000 to $180,000, comp sales are -10%.
Why can’t previous period revenue be zero when calculating comp sales?
The comp sales formula divides by previous period revenue. If previous period revenue is zero, the percentage change is undefined because division by zero is not possible. In that case, compare the raw revenue amounts instead of using a comp sales percentage.
