UK tax conversations online often collapse because people mix three different layers: statutory rules, personal allowances, and cash timing. Toollabz publishes small calculators that use effective percentages you supply so you can mirror an accountant spreadsheet without pretending HMRC math is hard-coded into a free webpage.
Self-employed sketches: profit, tax, NI in one line
The self employed tax calculator UK multiplies annual profit by income tax and NI percentages you enter. Class 2, Class 4, and personal allowance stacking are not auto-modeled because those rules move with budgets. Instead, bring the blended rate your advisor already put in a forecast and use the tool for reserves planning, not filing.
Payments on account also move cash timing. A model that only shows “after tax profit” still helps you decide how much to park in a business savings pot before January, even if it does not print HMRC forms.
Dividends: why “effective dividend tax %” is a planning hack
The dividend tax calculator UK applies one percentage to gross dividends. Real life has allowances, bands, and interactions with salary. The hack is intentional: directors often already have a blended rate from their accountant for board slides. Type that rate, get a net figure, and label the slide “illustrative.”
PAYE salary after tax UK: compare with sole trader sketches
The salary after tax calculator UK uses gross salary plus income tax, NI, and pension percentages. It is still not a payroll engine, but it is the right shape when someone asks “if I take this PAYE offer, what net hits my bank?” Pair it with the freelance pricing and day rate guide when you are choosing between employment and contracting routes.
Comparison: which calculator matches which life event
| Life event | Start here |
|---|---|
| Sole trader year-end reserves | Self employed tax calculator UK |
| Director distribution planning | Dividend tax calculator UK |
| PAYE offer evaluation | Salary after tax UK |
Common mistakes
- Typing statutory headline rates instead of blended effective rates from your forecast.
- Forgetting pension salary sacrifice changes both tax and NI bases.
- Mixing Scottish and rest-of-UK band assumptions without relabeling.
- Treating illustrative tools as HMRC submissions.
When to use these tools
- When you already have advisor percentages and need quick net figures for decisions.
- When comparing PAYE vs dividends at a whiteboard level.
- When building personal cash buffers before January balancing payments.
For wider money context, read net worth in five minutes and hourly vs salary framing. Australian readers can compare GST habits with GST inclusive vs exclusive.