How the variation calculation works
Add up the costs of the extra work and enter the total. Enter the markup percentage you want to apply to that cost. The calculator adds the markup and displays the resulting price, before tax.
Variation price = extra work cost × (1 + markup ÷ 100).
Worked example: $1,500 of extra work
With $1,500 of entered costs and a 25% markup, the markup is $375 and the proposed variation price is $1,875 before tax. The $375 is 20% of the selling price, so a 25% markup produces a 20% margin in this example.
Build up the cost before applying markup
Record the labour hours and rates, materials and quantities, subcontractor charges, equipment and other costs that relate to the change. Keep the scope clear so the same work is not also charged in the original quote.
Record the change as well as the number
A useful variation record identifies the project, who requested the change, what work is different, the reason for the change, drawing or evidence references, proposed value and any effect on timing. Record when the proposal was sent and any acknowledgement received.
Try the free browser-editable variation record template. You can enter the scope and pricing details, then print or save the completed record as a PDF.
Does a calculated price mean the customer has approved it?
No. This tool calculates a proposed price only. It does not obtain approval, interpret your contract or establish a right to payment. Check the requirements that apply to your job before proceeding with changed work.
Does this include tax or deductions for omitted work?
No tax is added. The calculator accepts a non-negative cost total. If a change includes omitted work or other adjustments, show those separately in your supporting record and check the final amount.
Should I enter margin or markup?
This calculator uses markup on cost. If you want to price from a target margin instead, use the builder margin calculator. Using the same percentage in each method produces different results.
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Published by Site Margin, operated by WB Built Pty Ltd. General planning tools; check inputs and job requirements before relying on a result.