Calculate average monthly sales from total annual sales and number of months, or find the missing value when two inputs are entered.
Average Monthly Sales Formula
The average monthly sales formula divides total sales by the number of months in the period.
AMS = TAS / M
The same relationship can be rearranged to calculate the other fields:
TAS = AMS * M
M = TAS / AMS
- AMS = Average monthly sales, in dollars per month
- TAS = Total annual sales, or total sales for the full period
- M = Number of months in the sales period
If you enter total annual sales and number of months, the calculator finds average monthly sales. If you enter average monthly sales and number of months, it finds total sales. If you enter total sales and average monthly sales, it finds the number of months represented by those sales.
Monthly Sales Period Reference
Use this table to match common reporting periods with the number of months to enter.
| Reporting period | Months to enter | Example use |
|---|---|---|
| Quarter | 3 | Q1, Q2, Q3, or Q4 sales average |
| Half year | 6 | First-half or second-half sales average |
| Full year | 12 | Average monthly sales for the year |
Example Calculations
Example 1: Calculate average monthly sales
You have total annual sales of $240,000 over 12 months.
AMS = 240000 / 12 = 20000
The average monthly sales are $20,000 per month.
Example 2: Calculate total sales
You average $18,500 in sales per month for 6 months.
TAS = 18500 * 6 = 111000
The total sales for the 6-month period are $111,000.
FAQ
Is average monthly sales the same as monthly revenue?
Average monthly sales can be the same as average monthly revenue if your sales figure represents revenue. The calculation does not adjust for refunds, discounts, taxes, expenses, or profit unless those items are already included in the sales number you enter.
Should the number of months always be 12?
No. Use 12 only when you are averaging a full year. If you are averaging a quarter, enter 3. If you are averaging six months, enter 6. The formula works for any sales period as long as the total sales and month count refer to the same period.
Why can average monthly sales hide seasonal changes?
An average spreads total sales evenly across the months. If one month is much higher or lower than the others, the average will not show that variation. For seasonal businesses, average monthly sales is useful as a summary, but you may still need to review each month separately.
