How it works
Copy the parts total and billed labor hours and rate from a written estimate for your vehicle. Add a diagnostic fee only if it is separate, and enter the quoted tax amount rather than guessing which items are taxable. If a component is already included elsewhere, do not add it again. The resulting invoice is arithmetic from your inputs, not a market-price prediction.
Subtract only confirmed credits that reduce the bill. A possible insurance or warranty reimbursement is not confirmed cash. The contingency is a separate reserve chosen for planning, not a fee the shop has charged or an authorization for extra work. Save a quote for comparison, then replace its amounts with another quote covering the same work.
The formula behind the estimate
Every result starts with a defined model and visible assumptions.
Labor = quoted billed hours × quoted hourly rate Invoice = parts + labor + separate diagnostic fee + other fees + quoted tax Payable quote = invoice − confirmed credit Additional reserve = payable quote × chosen contingency ÷ 100 Planning budget = payable quote + additional reserve
A worked example
An illustrative quote lists parts of 300, two billed labor hours at 100 per hour, a separate diagnostic charge of 75, other fees of 25 and tax of 40. The invoice is 640. With no credit and a chosen 10% reserve, an additional 64 makes the planning budget 704. These example amounts do not establish a typical repair price or labor rate in any location.
Quoted labor hours are not always elapsed workshop time
A shop may bill a specified labor allowance or actual time, depending on its pricing method. Use the billed hours and quoted rate in this calculator. If the shop supplies only a fixed labor total, you can enter one hour and that total as the rate to preserve the arithmetic. Ask for clarification rather than inferring hours from how long the car stays at the shop.
Use reliable evidence for each repair
The tool has no parts catalog, licensed labor-time database, diagnosis system or location-based market feed. A make, model or symptom alone cannot establish the repair required. Use an inspection and a quote from a suitable shop. Expensive or unclear work can justify a second opinion. A lower quoted total is not enough if the quotes omit different necessary work.
Credits, taxes and cash reserves
Use the final verified tax amount appropriate to the quote and your location. Confirm whether a warranty pays the shop directly or reimburses you later; only a reduction that actually applies to the payable quote belongs in the credit field. The comparison does not assess mechanical safety or decide whether a repair is essential. Resolve those questions with the technician.
Questions worth asking
Does this supply repair prices for my make and model?
No. It totals the amounts in your written quote. No model-specific prices or diagnostic conclusions are generated.
What if labor is quoted as one fixed amount?
Enter one billed hour and use the labor total as the hourly-rate input. Confirm the actual repair scope with the shop.
Should I add sales tax again to a tax-inclusive quote?
No. Count tax once. Separate it from other inputs or enter zero in the tax field when already included.
Is the contingency part of the shop's quote?
No. It is a separate cash reserve you choose for planning. It does not authorize additional work.
Can I compare two repair estimates?
Yes. Save the first result for comparison and enter the second quote using the same currency and repair scope. Changing currency clears the saved comparison.
This is general information, not personalized financial advice. Read the limitations.
