CIS refund checker
How much of the CIS taken off you may come back at the end of the year.
Free tools
Free tax calculators for small businesses.
Work out your CIS, your tax, your VAT and more, with every step of the working shown. Where Stoneledger has the same rule, the calculator uses the same engine as the software. No email, no sign-up, and nothing you type leaves your browser.
Construction Industry Scheme
CIS, from both sides.
CIS deduction calculator
What to deduct from a subcontractor's invoice, what to pay them, and what goes to HMRC.
CIS late return penalty calculator
What a late CIS300 costs, and when the next penalty starts.
Income Tax and Self Assessment
Your tax, and when it is due.
MTD checker
Whether Making Tax Digital for Income Tax applies to you, and from when.
Self-employed tax calculator
Income Tax and Class 4 National Insurance on your profit, and what you keep.
Payments on account calculator
Whether you have to make them, and how much is due on 31 January and 31 July.
Self Assessment penalty calculator
What a late tax return, or a late payment, costs on HMRC's scale.
Mileage allowance calculator
55p a mile from 6 April 2026: what you can claim, or be paid without tax.
Property
For landlords.
Landlord tax calculator
The Income Tax on your rent, with mortgage interest given as the 20% reduction.
Rental yield calculator
Gross and net yield, and what is left each month after mortgage interest.
Limited companies
For a company and its directors.
Corporation Tax calculator
19%, 25% and marginal relief between, with associated companies and short periods.
Dividend tax calculator
The tax on your dividends, band by band, after the £500 allowance.
Every business
VAT, and getting paid.
VAT calculator
Add VAT to a price, or take it out, at 20%, 5% or 0%.
Late payment interest calculator
What you can claim when another business pays you late: 8% plus base rate, and a fixed sum.
The same answers, from your own books, all year.
Stoneledger works these figures out from your own records as you go, and shows where every one came from.