Estimate total + allowance

Add the figures you actually have

This worksheet adds a percentage planning allowance, a fixed extra charge, and separate costs to a repair subtotal. The percentage is a personal contingency assumption. It is not a sales-tax calculator, a shop markup estimate, or a prediction of what a technician will find. Use the actual tax amount quoted by the shop in the separate-charges field if needed.

Formula: allowance plus other charge = subtotal × percentage ÷ 100 + fixed extra charge. Planning total = subtotal + allowance plus other charge + separate charges. With illustrative inputs of $4,000, 10%, $0, and $120, the allowance is $400 and the total is $4,520. All default dollar amounts are examples rather than market observations.

Do not include taxes, towing, rental, diagnostics, or core charges twice. A refundable deposit should still be budgeted for initial cash needs, but this worksheet does not track its later refund. An allowance is not authorization for a shop to perform additional work. Agree on a written spending cap and the method for approving changes separately. When the scope changes, revise your entered subtotal rather than assuming the allowance covers every risk.