Free UK money calculators

Test a budget split, size an emergency fund, decode a tax code, see leftover ISA room, and check Marriage Allowance — using 2026/27 UK figures.

Illustrative only. These tools run in your browser and do not send your numbers to us. They are general information, not HMRC, MoneyHelper or regulated financial advice. Confirm eligibility and figures on GOV.UK before you act.

50/30/20 budget split

Enter monthly take-home pay and what you actually spend on needs and wants. We show what is left for saving or extra debt payments, and the classic 50/30/20 targets for comparison.

Read the full 50/30/20 guide →

Needs share
Wants share
Left for future ()

Classic 50/30/20 targets:

Enter your monthly take-home pay to see the split.

Emergency fund target

Estimate how much cash buffer you need for 1–6 months of essentials, how far you have got, and how long a regular transfer would take to close the gap.

Build an emergency fund guide →

Target pot
Still to save
Time to target

Estimate monthly essentials to size your buffer.

Tax code decoder

Paste the code from your payslip or the HMRC app. We translate the common 2026/27 workplace codes (including S/C prefixes and emergency W1/M1 suffixes) into plain English.

Most employees entitled to the full Personal Allowance should see 1257L this tax year. If yours is different for more than a pay period or two after a job change, it is worth asking why.

Full tax-code guide →

Meaning
Tax-free amount
Nation

Type the code from your payslip or HMRC app, for example 1257L.

ISA allowance leftover

The 2026/27 ISA allowance is £20,000 across Cash, Stocks & Shares and Innovative Finance ISAs. A Lifetime ISA has its own £4,000 cap, and those deposits also count toward the £20,000.

Enter what you have already subscribed this tax year. We show room left and flag if a LISA amount looks over the cap.

ISA allowance guide → · Lifetime ISA guide →

Used of £20,000
Allowance left
LISA remaining

Enter year-to-date subscriptions. Lifetime ISA deposits count twice: toward the £4,000 LISA cap and the £20,000 overall allowance.

Marriage Allowance check

A simplified 2026/27 check: one partner at or under the £12,570 Personal Allowance and the other a basic-rate taxpayer (income above £12,570 and at or under £50,270 for most of the UK). Potential saving is up to £252 a year.

Full Marriage Allowance guide →

Basic eligibility
Indicative saving
Allowance transfer

Enter both incomes for a simplified check. Married or civil partners only.

After you use a tool

Pick one concrete next step: set a payday standing order, query a tax code with payroll or HMRC, apply for Marriage Allowance on GOV.UK, or start a one-month spending audit. Calculators help you see the numbers; the start-here paths tell you which move comes first.

Start here by situation Browse all guides