Useful next calculations
Rates and sources
UK company rates (Corporation Tax, VAT, payroll NI) as published by HMRC and Companies House.
Source: HMRC — Running a business. Check the linked guidance and any live quote before acting.
When to use this calculator
- Before pricing a job, setting margin targets or reviewing hiring costs.
- When you want to test sensitivity around volume, tax, markup or overheads.
- When you need a practical estimate before committing to a budget or proposal.
- When you are modelling break-even volume as costs or prices change.
A worked example
These are the example figures the calculator opens with.
| Input | Value |
|---|---|
| Subtotal (£) | £1,000 |
| VAT / Sales Tax Rate (%) | 20% |
| Discount (%) | 0% |
For those figures the calculator returns:
- Discount: £0.00
- Net: £1,000.00
- Tax: £200.00
- Total: £1,200.00
How to read your results
Tax
Review this figure alongside your gross income so you can understand deductions before the tax year closes. It is a planning estimate, not a filed return.
Method & assumptions
This calculator computes invoice totals by applying your chosen VAT rate to the net subtotal, then adding any additional line items or deducting discounts. The standard UK VAT rate is 20%, with a reduced rate of 5% applying to certain domestic and energy-related supplies. Enter your net (VAT-exclusive) amount and the applicable rate; the tool outputs the VAT amount and gross total separately.
Discounts are applied to the net figure before VAT is calculated, in line with tax authority rules for prompt payment discounts. The calculator does not store or transmit any data and is intended for quick estimation. For formal invoicing, always use compliant accounting software that produces records meeting Making Tax Digital requirements. Consult tax authority guidance or an accountant if you are unsure which VAT rate applies to your supply.
Common mistakes
- Using optimistic assumptions without testing a more cautious scenario.
- Using revenue in place of gross profit when calculating margin.
- Treating the result as a final quote instead of a planning estimate.
- Forgetting employer on-costs when modelling the true cost of a hire.
What to do next
- Try at least one more scenario so you can compare a realistic range.
- Use the related calculators below to cross-check the decision from another angle.
- Write down the key outputs from your best scenarios before you decide.
- If the result surprises you, change one input at a time to isolate the driver.