How do you calculate job costing variance?

Multiply the units with variance by the per-unit cost variance and the scope included, then add any fixed variance. With 420 units at $7.80, 100% scope and a $1,250 fixed overrun, variable variance is $3,276 and total variance is $4,526.

What does the cost variance per unit figure mean here?

It's the total variance spread back over the affected units — $4,526 across 420 units is about $10.78 per piece. That per-piece view tells you how much each part missed the estimate once the fixed overrun is included.

What is a favorable vs unfavorable variance?

An unfavorable variance means actual cost exceeded the quote, like the $4,526 overrun in the example. A favorable variance means you beat the estimate. Enter negative per-unit values to model jobs that came in under quote.

Why include a scope percent?

Sometimes only part of the run is affected by the variance — a tooling issue that hit the first portion, for example. Scope lets you apply the per-unit variance to the relevant share instead of the whole lot.

What's the fixed job variance amount for?

It captures one-time overruns that don't scale with quantity — extra programming time, a scrapped fixture, or expedited material freight. In the example it adds $1,250 on top of the $3,276 variable variance.

Job costing variance vs standard cost variance?

Standard cost variance compares actuals to a standard across all production; job costing variance is scoped to a single job against its specific quote. In a job shop the per-job view is what drives requoting decisions.

Contract Manufacturing, Job Shop Quoting & Make-to-Order calculator

Job Costing Variance Calculator

Job costing variance is the dollar gap between what a job was quoted to cost and what it actually cost once labor, material and overhead are booked. Cost accountants and shop managers use it to find where estimates drift from reality — a routing that runs slower than quoted, material that came in over, or a fixed overrun on tooling. It matters because a job shop lives and dies on estimate accuracy, and tracking variance per job is how you tighten the next quote and protect margin. This calculator combines a per-unit variance scaled by scope with a fixed variance amount to give the total dollar swing on a job.

What this calculator does

Estimate cost variance between quoted and actual job performance.
reviewing closed jobs and improving future quote accuracy
It computes total job costing variance as the per-unit variance times the units affected and the scope included, plus a fixed job variance amount.

Formula used

Variable job costing variance = parts or job units with variance × cost variance per unit × variance scope included
Total job costing variance = variable job costing variance + fixed job variance amount

Inputs explained

Parts or job units with variance:
Cost variance per unit:
Share of variance scope included:
Fixed job variance amount:

How to use the result

Use it during or after a job close to quantify how far actual cost ran from the quoted estimate.
It reports the size of the variance, not its cause; a large total doesn't tell you whether the driver is labor, material or a one-off tooling overrun without digging into the line items.

Current U.S. benchmarks

The U.S. prime lending rate is 6.75% (Federal Reserve via FRED, 2026-07-02). Payback and financing math should start from today's rate, not a remembered one.

Common questions

How do you calculate job costing variance? Multiply the units with variance by the per-unit cost variance and the scope included, then add any fixed variance. With 420 units at $7.80, 100% scope and a $1,250 fixed overrun, variable variance is $3,276 and total variance is $4,526.
What does the cost variance per unit figure mean here? It's the total variance spread back over the affected units — $4,526 across 420 units is about $10.78 per piece. That per-piece view tells you how much each part missed the estimate once the fixed overrun is included.
What is a favorable vs unfavorable variance? An unfavorable variance means actual cost exceeded the quote, like the $4,526 overrun in the example. A favorable variance means you beat the estimate. Enter negative per-unit values to model jobs that came in under quote.
Why include a scope percent? Sometimes only part of the run is affected by the variance — a tooling issue that hit the first portion, for example. Scope lets you apply the per-unit variance to the relevant share instead of the whole lot.
What's the fixed job variance amount for? It captures one-time overruns that don't scale with quantity — extra programming time, a scrapped fixture, or expedited material freight. In the example it adds $1,250 on top of the $3,276 variable variance.

Last reviewed 2026-05-12.