Free practical guide
How to calculate and explain KPI variance
A variance tells you how far a result is from a reference value, such as a budget or target. The arithmetic is simple. The difficult part is saying whether the difference is important and what caused it.
Start with two calculations
Absolute variance = actual − plan
Percentage variance = (actual − plan) ÷ plan × 100, when plan is non-zero and the comparison is meaningful.
Suppose Raket Parts planned €50,000 of operating costs but spent €54,000.
| Measure | Result |
|---|---|
| Planned cost | €50,000 |
| Actual cost | €54,000 |
| Absolute variance | +€4,000 |
| Percentage variance | +8% |
The cost variance is positive because actual cost is higher than planned. That is normally unfavourable for a cost-control measure. A positive sign does not mean a good result.
The direction matters
If revenue was €114,000 against a €100,000 target, the variance is +€14,000 (+14%). Higher revenue may be favourable. But even then, check whether the gain came with higher returns, discounting or costs.
Always name the definition and period. “Sales” might mean orders placed, invoices issued or cash received. Compare like with like before drawing a conclusion.
Percentage points are not percentage growth
If a conversion rate increases from 20% to 24%, it rises by 4 percentage points. The relative increase is 20%, because 4 ÷ 20 × 100 = 20. Calling both changes “4%” hides the distinction.
Investigate before you act
Break the total change into meaningful drivers such as price, volume, mix and timing. Check data quality and exclusions. Ask whether the deviation exceeds a materiality threshold. A precise calculation with an inconsistent definition is not a trustworthy KPI.
A useful way to report the result
“Operating costs were €54,000 against a €50,000 plan: €4,000 (8%) above plan. Investigate the increase by cost category before attributing it to a single driver.”
Explore related learning
Start with Data Literacy for Business Decisions to check the meaning of numbers, or compare the related glossary entries on budget variance and percentage points.
Put this into practice
Insyt is free. Practise these ideas against realistic business data and check your work as you go.
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