Variation Cost Calculator
Cost up a variation cleanly with labour, material, equipment, overhead, profit and GST.
General tool only. This calculator gives estimates based on the values you enter. Always check your contract terms and any state-specific rules before relying on the figures.
Include GST
GST is added after markup.
Results
Enter your variation costs to calculate the total claim.
How it works
Behind the numbers
A defensible variation includes direct costs, a share of project overhead, a profit margin, then GST on top. Document each line item — that's what gets approved.
Formula
The maths, written out
Direct = Labour + Material + Equipment + Sub Overhead = Direct × OH% Subtotal = Direct + Overhead Profit = Subtotal × Profit% Total = (Subtotal + Profit) × (1 + GST%)
Worked example
A quick scenario
$9,400 direct + 8% overhead ($752) = $10,152 subtotal; +12% profit ($1,218.24) = $11,370.24; +10% GST = $12,507.26 variation claim.
Frequently asked
Is this calculator free to use?
Yes. All calculators on Contractor Calc are free and do not require sign-up.
How accurate are the results?
The calculators use standard formulas. Results are estimates only and depend on the values you enter. Always check against your contract.
Can I export the results?
Most calculators include a download or copy-to-clipboard option for sharing with clients or storing in your records.