How do I work out the gross salary for a target take-home?

There is no simple algebraic formula because UK Income Tax + NI have multiple band thresholds and the Personal Allowance tapers above £100,000 of gross income. This calculator uses bisection: it tries a gross figure, computes the take-home through the standard PAYE engine, and adjusts up or down until the answer hits the target net within £1. Twenty-five iterations is usually enough.

Why does the gross for £80k net look so high?

Hitting £80,000 net requires a gross around £115,000-£120,000, well into the £100k-£125,140 Personal Allowance taper band. Every gross pound in that band carries an effective 62% deduction (40% IT + 2% NI + 20% PA loss), so you need a lot more gross to lift the marginal net.

Does this calculator handle Scottish bands?

Yes - the inverse calc wraps the salary engine, so changing the region to Scotland uses the Scottish Income Tax bands (Starter, Basic, Intermediate, Higher, Advanced, Top) for the underlying gross-to-net step. National Insurance is UK-wide so unchanged.

Can I include pension contributions?

Yes - if you sacrifice a percentage of salary into pension, set that percentage in the optional input and the search will find the gross salary that produces the target take-home AFTER the sacrifice deduction. This is the right model for "what salary do I need so that after my 10% pension sacrifice I still net £X".

Is there a closed-form formula?

For a single band the algebra is trivial: gross = (net - allowance_relief) / (1 - band_rate). But UK pay crosses up to five bands plus the taper, so building a closed-form solver is more code than just bisecting. The bisection approach also adapts automatically to any future band change without algebra rework.

Salary Needed for £X Take-home 2026/27

Reverse-engineer the gross UK salary you need to hit a target take-home. Useful for budgeting and contract negotiation: "I need to bring home £X, what gross am I asking for?". The calculator uses the same engine that powers the salary calculator, so the round-trip is exact.

Required gross for common take-home targets (2026-27)

Target take-home	Required gross	Effective marginal rate	Difference
£20,000	£22,890	28.0%	£2,890
£25,000	£29,834	28.0%	£4,834
£30,000	£36,778	28.0%	£6,778
£35,000	£43,723	28.0%	£8,723
£40,000	£50,763	42.0%	£10,763
£45,000	£59,384	42.0%	£14,384
£50,000	£68,005	42.0%	£18,005
£60,000	£85,246	42.0%	£25,246
£70,000	£103,796	62.0%	£33,796
£75,000	£116,955	62.0%	£41,955
£80,000	£128,705	47.0%	£48,705
£90,000	£147,573	47.0%	£57,573
£100,000	£166,441	47.0%	£66,441

Note how the gross-to-net gap widens disproportionately above the higher-rate threshold (£50,270) and especially in the £100,000-£125,140 PA-taper band where the effective marginal rate jumps to ~62%.

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Frequently asked questions

How do I work out the gross salary for a target take-home?: There is no simple algebraic formula because UK Income Tax + NI have multiple band thresholds and the Personal Allowance tapers above £100,000 of gross income. This calculator uses bisection: it tries a gross figure, computes the take-home through the standard PAYE engine, and adjusts up or down until the answer hits the target net within £1. Twenty-five iterations is usually enough.
Why does the gross for £80k net look so high?: Hitting £80,000 net requires a gross around £115,000-£120,000, well into the £100k-£125,140 Personal Allowance taper band. Every gross pound in that band carries an effective 62% deduction (40% IT + 2% NI + 20% PA loss), so you need a lot more gross to lift the marginal net.
Does this calculator handle Scottish bands?: Yes - the inverse calc wraps the salary engine, so changing the region to Scotland uses the Scottish Income Tax bands (Starter, Basic, Intermediate, Higher, Advanced, Top) for the underlying gross-to-net step. National Insurance is UK-wide so unchanged.
Can I include pension contributions?: Yes - if you sacrifice a percentage of salary into pension, set that percentage in the optional input and the search will find the gross salary that produces the target take-home AFTER the sacrifice deduction. This is the right model for "what salary do I need so that after my 10% pension sacrifice I still net £X".
Is there a closed-form formula?: For a single band the algebra is trivial: gross = (net - allowance_relief) / (1 - band_rate). But UK pay crosses up to five bands plus the taper, so building a closed-form solver is more code than just bisecting. The bisection approach also adapts automatically to any future band change without algebra rework.