Budget variance analysis
Last reviewed 2026-09-18
Budget variance analysis compares actual results with the budget and explains the difference. The whole subject turns on one decision: whether the budget you compare against is the one that was set, or the one that would have been set had you known the actual volume.
Static budget variance
The static budget variance is the simple comparison:
static budget variance = actual result − original budget
It answers “did we hit the plan?” and it is the right question for cash, headcount and committed spend. It is the wrong question for anything that scales with volume, because it mixes two unrelated stories: you sold a different number of things, and each thing cost a different amount. A production line 20% above plan will show an unfavourable materials variance no matter how efficiently it ran.
Flexible budget variance
A flexed budget restates the budget at actual volume, holding budgeted rates. That splits the static variance into two variances that mean different things:
| Variance | Formula | Answers |
|---|---|---|
| Sales volume variance | flexed budget − static budget | What did selling a different quantity do? |
| Flexible budget variance | actual − flexed budget | At that quantity, how well did we run? |
| Static budget variance | actual − static budget | The sum of the two |
Worked
Budget: 1,000 units, materials at 60.00 per unit, budgeted materials cost 60,000. Actual: 1,200 units, materials cost 76,800.
- Flexed budget = 1,200 × 60.00 = 72,000
- Sales volume variance = 72,000 − 60,000 = 12,000 unfavourable — the cost of making 200 more units, which is not a performance problem.
- Flexible budget variance = 76,800 − 72,000 = 4,800 unfavourable — the part that is about price or usage.
- Static budget variance = 76,800 − 60,000 = 16,800 unfavourable.
The static figure of 16,800 is arithmetically correct and managerially useless. Of it, 12,000 is the direct consequence of a volume decision somebody presumably wanted, and 4,800 is the number a production manager can act on.
Four traps
- Unequal periods. A 4-5-4 retail calendar gives some periods five weeks. Comparing a five-week actual to a four-week budget produces a 25% variance that nobody caused. Check comparability before computing anything; if the periods are not comparable, say so instead of footnoting it.
- Currency. A subsidiary's variance in group currency contains rate movement. Decompose in the transaction currency, translate the result, and name the rate, the rate type and the rate date — a missing rate should block the comparison, never default to one.
- Re-forecast drift. Comparing against a forecast that has been revised four times reliably shows small variances, because the target moved. If that is the comparison, say which version and when it was locked.
- Allocations. A variance on an allocated cost is frequently a variance in the allocation basis, not in the cost. Check the driver before investigating the department.
What the report should say when it cannot answer
Where a variance cannot be attributed, the honest output names the amount, the owner and the evidence needed — not a driver called “other”. And where the comparison itself is invalid (different calendars, a missing rate, an incomplete population), the report should refuse the comparison and state which field is missing and which conclusion it blocks. A qualified number gets quoted without its qualification; a refusal does not.
Common questions
- What is budget variance analysis?
- It is the comparison of actual results with budget and the explanation of the difference. Done properly it separates the effect of operating at a different volume from the effect of operating at different rates.
- What is the budget variance formula?
- Static budget variance is actual minus original budget. Sales volume variance is flexed budget minus static budget. Flexible budget variance is actual minus flexed budget, where the flexed budget is actual volume at budgeted rates. The last two sum to the first.
- When is a flexible budget worth the effort?
- Whenever the cost or revenue scales with volume, which covers materials, direct labour, commission and most variable overhead. For fixed costs it adds nothing, because the flexed budget equals the static one.
About Valcenra
Valcenra decomposes a financial movement into drivers that tie to the underlying records, keeps rounding, unmatched and unexplained residuals apart rather than summing them, and refuses to state a conclusion it cannot support — naming the field it needs and the conclusion that field decides. It is read-only: it drafts and computes, and it does not post journals, move money or approve anything. Talk to us.