Percent Variance Formula: Sign, Base, and Meaning

Apply the percent variance formula with an explicit reference value, interpret signs for revenue and expense, and handle zero-base cases correctly.

Quick answer

The percent variance formula is (comparison value - reference value) / reference value x 100%. For an actual-versus-budget question using budget as the base, write percent variance = (actual - budget) / budget x 100%. State the convention before calculating.

Put the reference value in the denominator

The formula has three jobs: measure the dollar change, scale that change to a meaningful base, and preserve direction. Favorable or unfavorable is a separate interpretation. A positive number means actual exceeds the declared reference, not automatically that performance is good.

This page owns the generic formula, denominator, sign, and worked interpretation. Broad planning, flexible-budget, price, quantity, efficiency, and mix analysis remains outside this narrow owner and within the BAR section.

Worked example: one sign, two meanings

1Revenue was budgeted at $500,000 and actual revenue is $525,000. Dollar variance is $525,000 - $500,000 = +$25,000. Percent variance is $25,000 / $500,000 x 100% = +5%. If more revenue is desirable and the comparison is otherwise valid, label it favorable.
2Expense was budgeted at $300,000 and actual expense is $330,000. Dollar variance is $330,000 - $300,000 = +$30,000. Percent variance is $30,000 / $300,000 x 100% = +10%. If lower cost is the objective, the positive variance is unfavorable.
3Both calculations have a positive sign because actual is above budget. Their performance labels differ because revenue and expense have different objectives. Never replace that reasoning with a rule that positive always means favorable.
4Apply the same four-column setup in free BAR practice: reference, comparison, signed difference, and percentage. Add the favorable or unfavorable label only after reading the account and the question objective.

Percent variance formula in three steps

Step	Formula	Purpose
Dollar variance	Actual - Budget	Preserve direction in dollars
Relative variance	(Actual - Budget) / Budget	Scale the change to the stated reference
Percent variance	[(Actual - Budget) / Budget] x 100%	Express the relative change as a percentage

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Separate arithmetic sign from business meaning

1For revenue, actual above budget is commonly favorable and actual below budget commonly unfavorable, assuming the revenue is desirable and measured consistently.

2For expense, actual above budget is commonly unfavorable and actual below budget commonly favorable, unless the underspending reflects missed activity, quality problems, or another adverse result.

3For profit or contribution margin, higher is commonly favorable. For defect rate, cycle time, or another nonfinancial measure, interpret the direction from the objective rather than an accounting label.

4If the problem defines variance as budget minus actual instead, the arithmetic sign reverses. Follow the supplied convention and keep the favorable or unfavorable explanation consistent with it.

Revenue and expense variance worked example

Line item	Budget	Actual	Dollar variance	Percent variance	Meaning
Revenue	$500,000	$525,000	+$25,000	+5%	Favorable if higher revenue is the objective
Expense	$300,000	$330,000	+$30,000	+10%	Unfavorable if lower spending is the objective

Handle zero and negative reference values

When the reference value is zero, the usual percent variance is undefined because the formula divides by zero. Report the dollar variance and write that the percentage is not meaningful unless the problem provides another valid base. Do not substitute one as the denominator or call the change 100%.

A negative reference can also make the percentage difficult to interpret. Moving from a $100 loss to a $20 loss is an $80 improvement, but a mechanical ratio using -$100 produces a negative sign. Explain the underlying movement and use the convention the problem supplies.

Very small bases can create large percentages from modest dollar changes. A complete answer gives both the dollar and percentage variance so scale is visible.

Interpret a percent variance without guessing

1Name the referenceWrite budget, prior period, standard, or other supplied base before selecting the denominator.
2Compute the signed differenceSubtract the reference from the comparison value and keep the positive or negative direction.
3Test the denominatorIf the reference is zero, stop the usual percentage calculation and report the dollar change.
4Assign meaning separatelyUse the line-item type and stated objective to classify favorable or unfavorable, not the sign alone.

Do not confuse percent with percentage points

If a margin rises from 20% to 25%, the percentage-point change is 25% - 20% = 5 percentage points. The relative percent change is (25% - 20%) / 20% x 100% = 25%. They answer different questions.

Use percentage points when comparing two rates directly. Use percent change when scaling the difference to the original rate. Label the unit in the final answer so a reader cannot mistake 5 points for 5%.

The Blueprint explains the BAR testing framework, but it does not turn this one generic formula into the complete variance-analysis curriculum. Use the CPA Exam Blueprints for scope and CPA practice questions after the focused drill.

Percentage traps and correct reporting

Situation	Correct treatment	Example result
Actual $120, budget $100	Use budget as the declared reference	+20%
Rate rises from 20% to 25%	Report relative change and point change separately	+25% relative; +5 percentage points
Actual $100, budget $0	Do not divide by zero	$100 dollar variance; percent not meaningful
Formula supplied as Budget - Actual	Follow the stated convention and relabel the sign	Do not mix conventions mid-solution

Use a denominator-first variance check

Write the comparison value and reference value with their dates, units, and labels.
Subtract reference from comparison unless the problem explicitly supplies another convention.
Divide by the declared reference value and multiply by 100%.
If the reference is zero, stop and report the dollar change rather than inventing a percentage.
Interpret favorable or unfavorable from the line item and objective, not from the sign alone.
Distinguish relative percent change from percentage-point change before selecting the final unit.

Frequently asked questions

What is the percent variance formula?

When budget is the reference, percent variance = (actual - budget) / budget x 100%. More generally, percent change = (new value - reference value) / reference value x 100%. State the denominator because another convention can reverse or rescale the result.

Does a positive percent variance mean favorable?

Not by itself. A positive revenue variance is generally favorable when more revenue is desirable, while a positive expense variance is generally unfavorable when spending exceeded budget. The business objective and line-item type control the interpretation.

What happens when the budget is zero?

The usual percentage is undefined because division by zero is not valid. Report the dollar variance and label the percentage not meaningful unless the problem gives another approved base.

Are percent variance and percentage-point change the same?

No. A rate moving from 20% to 25% rises by 5 percentage points but by 25% relative to the 20% reference. State which result the question requests.

Sources

AICPA 2026 Uniform CPA Examination Blueprints (retrieved 2026-08-11)
BLS Calculating Percent Changes (retrieved 2026-08-11)