Free final account calculator

By Alex Williams, director of Ty Parc Construction, a building contractor in Newport, South Wales · Last reviewed 21 October 2026

Enter the contract price, every extra, credit and payment. The calculator works out the final total and balance to the penny. Nothing is saved — it all stays in your browser. Background: what is a final account?

Contract price (£)

VAT

Amounts include VATAmounts exclude VAT

Extras

Extra 1 description

Amount (£)

Date agreed

Status

Credits

Credit 1 description

Amount (£)

Payments made

Enter what was actually paid, including VAT.

Payment 1 date

Amount (£)

Final account

Amounts include VAT.

Original contract: £0.00
+ Agreed extras: £0.00
− Credits: £0.00
= Final total: £0.00
− Paid: £0.00
= Balance due: £0.00

The printout includes a “Signed off by both parties” block, so it doubles as the final account sign-off sheet.

How to use this calculator

Enter the contract price from the quote or contract, and choose whether your figures include VAT.
Add every extra with its amount, the date it was agreed and how — in writing, verbally, or not agreed.
Add credits for anything left out or changed to something cheaper.
Add every payment already made.
Check the balance, then print or download the summary and both sign it off.

If you can’t agree the figure, see what to do in a dispute. Builders chasing an unpaid balance can use the letter before action generator.