Isolate the total unit-volume effect at the budgeted sales mix and standard unit contributions. This does not estimate actual product-level sales or price effects.
Unit-volume change × budget-mix weighted standard contribution
Enter compatible inputs and calculate, or load the complete example.
ONE CLEAR WORKING QUESTION
Budget shares of 3/5 and 2/5 stay fixed when total units move from 5 to 8; hypothetical allocations of 4.8 and 3.2 are not actual product sales.
3 units and 2 units, total 54.8 hypothetical units and 3.2 hypothetical units, total 8Budget shares of 3/5 and 2/5 stay fixed when total units move from 5 to 8; hypothetical allocations of 4.8 and 3.2 are not actual product sales.
THE FIELD NOTES
Use the result now, then read the practical notes for assumptions, examples, limitations, and the choices behind it.
Budget total 5; weighted contribution USD 0.55 per unit. Three additional fixed-mix units produce USD 1.65, not an observed revenue change.
Enter each product's budgeted units and standard contribution per unit in matching row order, then enter actual total units for the group. Use USD, one period and compatible unit definitions throughout. The calculation holds budget shares constant to isolate the contribution effect of the total quantity change.
The budget totals 5 units with a weighted standard contribution of USD 0.55 per unit. Three additional units at that fixed mix produce a favorable USD 1.65 contribution effect. This is a hypothetical decomposition, not an observed revenue change.
Use the contribution margin calculator to establish the standard contribution basis, then the sales growth calculator for a separate observed revenue comparison. Quantity variance does not identify actual sales mix, price effects or causes.
Negative standard contributions are allowed: more units of a loss-making fixed mix can be unfavorable. The total is calculated from exact unrounded effects. When rounded row amounts differ from the rounded total, the difference is shown explicitly rather than silently assigned to a product.
THE PRODUCT IS NEXT
Enter each product's budgeted units and standard contribution per unit in matching row order, then enter actual total units for the group. Use USD, one period and compatible unit definitions throughout. The calculation holds budget shares constant to isolate the contribution effect of the total quantity change.
The budget totals 5 units with a weighted standard contribution of USD 0.55 per unit. Three additional units at that fixed mix produce a favorable USD 1.65 contribution effect. This is a hypothetical decomposition, not an observed revenue change.
Use the contribution margin calculator to establish the standard contribution basis, then the sales growth calculator for a separate observed revenue comparison. Quantity variance does not identify actual sales mix, price effects or causes.
Negative standard contributions are allowed: more units of a loss-making fixed mix can be unfavorable. The total is calculated from exact unrounded effects. When rounded row amounts differ from the rounded total, the difference is shown explicitly rather than silently assigned to a product.
No. It holds the budgeted mix constant and isolates the total quantity change. Actual mix changes and price effects are different decompositions and are not calculated here.
Yes. Signed contributions are retained. Selling more of a loss-making fixed mix can be unfavorable, so the result sign comes from the exact contribution effect rather than the unit change alone.
The total uses exact unrounded effects before final display rounding. If separately displayed row amounts do not sum to the displayed total, the tool shows the signed rounding difference rather than assigning it silently to a product.
BUILT BY LOOK ATLAS
Turn a simple product photo into polished, campaign-ready creative for your store, ads, and social channels. No studio. No reshoots.
Create your first shoot free, then keep going when you’re ready.