Rates & sources
UK tax rates and thresholds, as published by HMRC. Scotland and Wales have devolved rates for income tax and property transactions.
Source: HMRC — Tax rates — figures refreshed at the start of each tax year.
When to use this calculator
- Before accepting a pay change, bonus, pension contribution, or salary-sacrifice option.
- When you want to compare employed, self-employed, or dividend-based income scenarios.
- When you need a simple take-home estimate before running payroll or filing returns.
- When you are approaching the £100,000 income level and want to understand the personal allowance taper effect.
- When you are planning a salary sacrifice arrangement and need to see the net pay impact before agreeing terms.
A realistic New Zealand planning example
Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.
Amount (NZ$)
1000
Calculation Type
Add GST to ex-GST price (exclusive → inclusive)
GST Rate
15% (standard NZ rate)
After entering these figures, review ex-gst price, gst amount and gst-inclusive price together rather than in isolation — each metric tells a different part of the story. Then rerun the tool with one input adjusted to see which variable has the biggest effect on all three outputs before you settle on a plan.
How to read your results
Ex-GST Price
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
GST Amount
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
GST-Inclusive Price
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
GST Rate
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Method & assumptionsAuthoritative sources
New Zealand’s Goods and Services Tax (GST) has been charged at a flat rate of 15% since 1 July 2010, making it one of the simplest consumption taxes in the world. Unlike the UK’s VAT system, which has multiple rates, virtually all goods and services in New Zealand are taxed at the same rate — the main exceptions being zero-rated supplies such as exported goods and some financial services, and exempt supplies such as residential rent. Businesses registered for GST charge the tax on their sales, claim it back on their business purchases, and pay the net difference to Inland Revenue on a regular filing schedule. This calculator covers all three common calculations: adding GST to a price to produce a customer invoice total, removing GST from a quoted inclusive price to find the base cost, and identifying the GST component within an inclusive price for accounting purposes.
Getting the direction of your calculation right matters for accurate invoicing and GST return filing. Adding 15% to an ex-GST price (multiplying by 1.15) gives the GST-inclusive total. Removing GST from an inclusive price requires dividing by 1.15 — not subtracting 15% — because 15% of the inclusive price is not the same as 15% of the base price. For example, a $115 GST-inclusive price contains $15 of GST (13.04%), not $17.25. This calculator handles the correct formula in each direction so your figures are compliant with IRD requirements. For further guidance on GST registration, filing, and invoicing obligations, visit ird.govt.nz/gst.
Common mistakes
- !Entering gross income when you really want take-home pay, or vice versa.
- !Ignoring pension contributions, deductions, or local tax rules that change the result.
- !Comparing monthly and annual figures without standardising them first.
- !Overlooking the National Insurance threshold changes that apply mid-year when rates or bands are adjusted in a Budget.
- !Assuming a salary sacrifice benefit reduces take-home pay by the full gross amount, rather than only the after-tax cost.
What to do next
- Check the same scenario with related pay or deduction calculators to see the full picture.
- Keep a copy of the assumptions you used so you can compare next tax year or pay period accurately.
- Read the related guides below if you are choosing between multiple income or deduction options.
- If you are self-employed, run the self-employment tax calculator alongside this result to compare the net position against employed income.
- Check whether increasing your pension contribution by even one or two percent changes the take-home significantly — use the pension calculator next.
Frequently asked
Use arrow keys to navigate items, Enter or Space to expand/collapse.
End-of-article next steps
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