How this works
UK take-home pay is what lands in your bank account after the cascading deductions HMRC pulls before you ever see it. There are four big ones and a few smaller modifiers. **Income Tax** uses the 0 / 20 / 40 / 45 % bands with the £12,570 personal allowance (tapered above £100k). **National Insurance Class 1** for employees takes 8 % on earnings £12,571 – £50,270 and 2 % above. **Pension** is the lever that bends the whole calculation: salary sacrifice reduces your taxable salary at source (cutting both tax and NI), while an after-tax personal pension reduces take-home only and gets its tax relief via a different mechanism. **Student loan** is the last big bite — 9 % above the plan-specific threshold for Plans 1, 2, 4, 5, or 6 % above £21,000 for Postgrad.
The order matters because each layer feeds the next. The widget runs it as: (1) take salary sacrifice off gross, (2) compute Income Tax on the reduced figure, (3) compute NI on the same reduced figure, (4) compute student loan on the reduced figure, (5) subtract a non-sacrifice pension from take-home only. The result row shows the annual figure, divides by 12 for monthly and 52 for weekly. Monthly is the most useful comparison since most UK employers pay monthly.
What this doesn't model: Scotland's separate income-tax bands (use the Scotland income-tax calculator for the tax part, then NI and the rest are the same), non-standard tax codes (1257L is assumed throughout), benefits in kind reported via your tax code, employer NI (13.8 %, which sits on top of your salary and isn't your problem), the additional 1.25 % Health and Social Care Levy (cancelled before it took effect), and any salary above the £100k taper that triggers personal-allowance erosion above the standard formula.
The formula
Personal allowance, bands, NI thresholds and student-loan thresholds are the 2024/25 published figures and frozen until 2027/28 at time of writing. Plan 4 thresholds belong to Scotland but are paid by Scottish-resident students regardless of where they work, so the calculator uses the Plan 4 threshold whenever Plan 4 is selected. The plan 3 / postgraduate loan is treated as a single 6 %-above-£21,000 deduction — if you have both a Plan 1/2/4/5 loan AND a postgraduate loan, the actual deductions stack but the widget currently only supports one at a time.
Example calculation
- Gross £35,000, 5 % salary-sacrifice pension, Plan 2 student loan.
- Pension £1,750 off gross → effective gross £33,250. IT = £4,136. NI = £1,654. Student loan = (33,250 − 27,295) × 9 % = £536.
- Total deductions £8,076 → net annual ≈ £26,924 (~£2,244/mo, ~£518/wk). Effective rate 23.1 %.
Frequently asked questions
Why is salary sacrifice so much better than after-tax pension?
Because salary sacrifice escapes National Insurance entirely. A higher-rate taxpayer paying £100 of pension by sacrifice loses £58 of take-home — the contribution costs £100 but they would have only seen £58 of it as cash anyway (£100 minus 40 % tax and 2 % NI). Doing the same contribution after-tax loses the same £58 in take-home AND the pension only gets topped up to £100 via 20 % basic-rate relief plus a reclaim through self-assessment — extra paperwork, slower flow, and the employer's NI saving (13.8 %) doesn't make it back to you. Across the workforce salary sacrifice has become near-universal for workplace pensions because the maths is decisive.
I have two student loans (Plan 2 + Postgrad). How do I model that?
The widget only handles one plan at a time right now, so it under-reports your deductions. As a workaround, pick Plan 2 in the dropdown and then add 6 % × max(0, salary − £21,000) manually to the student-loan line. For a £35,000 salary that's an extra £840/year ≈ £70/month on top of what the calculator shows. The two loans stack: HMRC actually deducts both each pay period because they're tracked separately at the Student Loans Company. We'll add a "stacked" option in a future update.
What if I live in Scotland?
The Income Tax part of this calculator will be wrong for you — Scotland has its own six-band income tax (starter 19 % to top 48 %) set by the Scottish Parliament, while NI, pension treatment and student loan are reserved to Westminster and so identical to the rUK figures. For a full Scottish take-home, run the Scotland Income Tax Calculator for the tax part and add the NI / pension / student-loan deductions from this widget back on. We'll ship a dedicated Scottish take-home calculator alongside the planned country switcher expansion.