Job Costing Calculator: Compare Your Estimate With Actual Costs

See both the bid and the outcome

A bid calculation asks what you need to charge for the costs you expect. Job costing asks what the work actually consumed. Use the calculator below for the first question and the job-cost variance worksheet (.xlsx) for the second.

The worksheet includes a clearly hypothetical remodel with $25,000 of estimated cost and $27,900 of actual cost. A $1,800 approved change increases modeled revenue, but the $2,900 cost overrun still leaves $1,100 less modeled profit than planned. You can change every input to examine your own job. No signup is required.

The examples use entered costs and simple arithmetic. They are not market prices, industry profit benchmarks, or a record of a real contractor's results.

Use the calculator to check the price you are building

Enter material cost, burdened labor, equipment, and the job's allocated overhead, then apply the markup percentage. The existing calculator shows entered cost, bid price, and the difference between them. That difference is modeled profit only to the extent that the inputs include all relevant costs.

For the calculator's $25,000 base-cost example, a 15% markup adds $3,750 and produces a $28,750 bid price. The $3,750 is 13.04% of the bid price. Markup and margin use different denominators: markup divides the addition by cost; margin divides profit by revenue. The markup-versus-margin calculator lets you check that conversion.

Account for subcontractors, permits, delivery, warranty exposure, and other applicable costs. If the on-page input categories do not fit a cost, include it explicitly in the worksheet rather than silently omitting it. Do not count the same labor or overhead in two categories.

A remodel with more revenue and less modeled profit

The following synthetic example is a separate job scenario from the markup calculator's default bid. It starts with a $32,000 contract. The original entered cost estimate is $25,000, so planned modeled profit is $7,000.

Cost category	Estimate	Actual	Overrun
Materials	$12,000	$13,200	$1,200
Burdened labor	$8,500	$9,800	$1,300
Equipment	$1,500	$1,700	$200
Allocated overhead	$3,000	$3,000	$0
Subcontractors	$0	$0	$0
Other job costs	$0	$200	$200
Total	$25,000	$27,900	$2,900

An approved $1,800 scope change brings modeled revenue to $33,800. Subtract $27,900 of entered actual costs and modeled profit is $5,900. Planned margin was $7,000 / $32,000 = 21.88%. The resulting modeled margin is $5,900 / $33,800 = 17.46%.

The reconciliation is short: $1,800 of additional revenue minus $2,900 of additional cost equals a $1,100 reduction in modeled profit. The change order increased the contract value; it did not offset every cost increase. Approval is not evidence that the customer has paid.

Use the worksheet without hiding missing costs

Open the workbook and replace the amber estimate and actual-cost cells. Keep the same categories on both sides. Enter 0 for a category that genuinely has no cost. Leaving a required cost blank keeps the affected totals and profit calculation blank, so a missing invoice is not quietly treated as free work.

Enter the original contract amount and the approved changes. The worksheet carries the original contract into the final column and calculates revenue, modeled profit, margin, and the change in profit. A zero-revenue case leaves the margin percentage blank because that ratio is undefined.

The notes column is where the exercise becomes useful. Split a material overrun into quantity, purchase-price, waste, or scope causes. Split labor into hours and loaded-rate changes. Then identify which estimating assumption should change on the next comparable job. An overrun caused by added scope may require a different response from an overrun on the original scope.

Keep the cost definitions consistent

GAO's cost-estimating guidance includes updating estimates with actual costs. This worksheet adapts that general discipline to a small job comparison; it is not a full implementation of GAO's program-cost framework. Source: GAO Cost Estimating and Assessment Guide.

Use a labor cost that includes the employer costs you intend to allocate, not a mixture of wage-only estimates and fully loaded actuals. Use the same overhead policy in the estimate and the actual column. Separate sales tax collected for remittance from revenue available to cover the work.

For an unfinished job, paid-to-date spending does not establish the cost at completion. Add expected remaining commitments and work before interpreting the result as a final margin. The current worksheet has one actual/current cost column; document whether it contains final actuals or an explicit forecast to complete. Do not mix those meanings across categories.

Turn the finding into a better next bid

Choose one completed job with a scope you can reconstruct. Gather the accepted estimate, approved changes, supplier invoices, time records, subcontractor costs, and the overhead allocation. Reconcile those inputs before drawing a conclusion about the estimator or crew.

In the example, labor is the largest cost overrun at $1,300. That is a reason to inspect hours and loaded rate, not proof that labor productivity caused the whole problem. Materials are close behind at $1,200; the supplier quote comparison guide provides a way to separate unit-price comparisons from delivery and pack-size effects.

Keep a short record of the assumption you changed and the next job on which you will check it. Repeated comparable jobs can reveal a useful pattern. A single job with changed scope is not an industry benchmark.

What this tool does and does not establish

The calculator and workbook operate on the numbers entered. They do not estimate local material prices, validate payroll or tax treatment, prove payment, or calculate company-wide net income. An overhead allocation does not guarantee every company expense has been recovered.

A positive modeled job profit can coexist with a cash shortage if customers have not paid or the business has other obligations. Keep cash collection and job-cost analysis as separate checks. If you need to evaluate software for maintaining these records, use the estimating software comparison and demonstrate the actual cost-code handoff before buying.