- Your tax snapshot on the home page. See what you’ve recorded this year, your estimated tax, and exactly how much to set aside each month — all at a glance when you log in.
- Self-employed expenses. Enter your monthly expenses and tax is now calculated on your profit (income minus expenses), giving you a much fairer estimate than before.
- Set-aside target in results. The calculator now tells you how much to save each month (and each week) toward your HMRC bill, so there are no surprises on payment day.
- Live “How to Pay” figures. The How to Pay page now uses your own up-to-date numbers instead of generic examples, so the guidance matches your real situation.
- Tax-year awareness. The app automatically works out which UK tax year your income belongs to and labels your results clearly (e.g. 2026/27).
- Centralised rates & clearer disclaimers. Tax rates and allowances are now held in one place so they’re easy to update each year, and results consistently note that figures are an estimate, not official HMRC advice.
For the self-employed
Keep a closer eye on your tax.
Track monthly income, estimate your UK self-employed tax, and see the deadlines you need to remember.
Today:
Current tax year:
What’s new
Income and tax estimate
You must be logged in before using this calculator.
Add each day for the month. Use the calendar to record what you earned on each day.
Pick only the dates you want to count. This helps if you have irregular work.
Subtract your business costs for the same period. Tax is only charged on your profit (income minus expenses), so this makes your estimate more accurate.
Dashboard
Loading your summary...
How to pay HMRC as a self-employed person
31 January
This is the final self-assessment deadline for the previous tax year. You submit your tax return, pay any balancing payment still owed, and make your first advance payment toward the current tax year.
31 July
This is your second advance payment toward the current tax year. If you have already paid some in January, this second payment covers the rest of that year’s estimate.
What you are actually paying
HMRC is not asking for a flat monthly bill from everyone. The bill is based on your total yearly profit, not just one month of income. This means your monthly earnings can vary a lot, but your tax bill still depends on what you made over the full tax year.
When to think about it
If you earn £300 in one week, £1,500 in another, or nothing for a few weeks, that is normal for self-employed work. The key is to keep records, add everything up, and estimate your tax as you go.
Based on your current estimate
Log in and calculate your income to see your live HMRC estimate.
How to pay
- Log in to your HMRC Government Gateway account and open your Self Assessment account.
- Check the amount due for the tax year, including any balancing payment and the advance payment.
- Choose how you want to pay: online bank transfer, debit card, or direct debit, depending on what is available.
- Use the payment reference shown to you in HMRC’s online system, then confirm the amount and complete the payment.
- Keep a copy of the payment confirmation in case you need to check it later.
Examples based on your current numbers
Current estimate
Your live estimate will appear here after you enter income and calculate.
What changes the bill
As your yearly income changes, your tax and National Insurance estimate changes too because HMRC calculates the bill using your total annual profit.
How your estimations are calculated
1. Annual income is projected
You enter your income for a single month, week, set of days, or a fixed annual amount. The calculator converts that into a yearly figure. Monthly amounts are multiplied by 12, weekly amounts by 52, and per-day entries by 12 (treating the days you entered as one month).
2. Your annual profit is estimated
For a simple estimate this calculator treats your income as your profit, before expenses. In reality self-employed tax is based on profit, so real-world figures can be lower once you subtract business costs.
3. Income tax is applied
An estimate uses the current UK personal allowance of £12,570. You pay no income tax on profit up to that amount. The next £37,700 is taxed at 20%, and anything above that is taxed at 40%.
4. Class 4 National Insurance is added
Self-employed people pay Class 4 National Insurance on profits above £12,570. The rate is 6% up to £50,270 and 2% above that. This is added to your income tax to give a total bill.
5. Take-home pay is your profit minus tax
Your estimated take-home is the annual profit minus your total tax bill. This is split by 12 to show a rough monthly take-home, just so you can picture what you might keep.
6. HMRC due dates are calculated
Self Assessment balances are normally paid in two instalments: 31 January and 31 July. Each is half of your total estimated bill for the year (shown as the "advance payments" on your estimate).
Important to know
These figures are an estimate, not an official HMRC calculation. They use simplified rates and treat your income as full profit. Your exact bill depends on real expenses, other income, and the exact rates for your tax year. Always check your figures with HMRC's official Self Assessment tools or a qualified accountant.