Budget Calculator UK 2025
The only free UK budget calculator with irregular income support, sinking funds, a method switcher, and a savings goal timeline. No sign-up. No ads.
Budgeting Method
Income Type
💰 Sinking Funds — Annual Expenses
Enter the yearly total — we convert to monthly automatically
➕ Custom Expenses
Savings Goal
— we'll tell you when you'll hit itThe 50/30/20 Budget Rule
50%
Needs
- Rent / mortgage
- Council tax
- Utilities
- Groceries
- Insurance
- Minimum debt payments
- Childcare
30%
Wants
- Dining out
- Entertainment
- Holidays
- Gym
- Subscriptions
- Clothing
- Hobbies
20%
Savings & Debt
- Emergency fund
- ISA / pension
- Investments
- Extra debt payments
- House deposit
- Future goals
Important: The 50/30/20 rule uses after-tax take-home pay as the base — not gross salary. If you live in London or another high cost-of-living area, your needs may legitimately exceed 50%. That's fine — adjust the percentages to what works for your situation. The framework is a guide, not a rule.
Zero-Based Budgeting
Zero-based budgeting means every pound of income is allocated to a specific category before the month begins — including savings. Income minus all allocations = exactly zero. It's the most rigorous budgeting method and is particularly powerful for people paying off debt, as it forces intentional decision-making about every pound.
Forces you to decide where every pound goes before you spend it
Excellent for aggressive debt payoff — every surplus is pre-allocated
Eliminates 'mystery spending' at the end of the month
Requires a complete budget re-do each month as income/expenses change
More time-intensive than simpler methods
Difficult to implement with genuinely irregular income
Budgeting With Irregular Income
Freelancers, contractors, commission earners, and seasonal workers face a budgeting challenge that no mainstream calculator addresses: your income varies every month. Here's the framework that works.
Budget from your worst month
Identify your lowest income month over the past year. Build your essential expenses budget around that figure. If you can't cover essentials on your worst month, you need to either reduce expenses or build a larger buffer first.
Build an income buffer first
Before aggressively saving or investing, build a 2–3 month income buffer in a separate account. This smooths out the feast-and-famine cycle. Think of it as your operating capital, not your emergency fund.
Use sinking funds for irregular expenses
Annual costs (car MOT, insurance renewals, Christmas, holidays) feel manageable when you divide them by 12 and save monthly. Our sinking funds section above handles this automatically.
Allocate surplus months intentionally
In higher-income months, follow a waterfall: (1) top up your income buffer, (2) max out tax-efficient savings (ISA, pension), (3) prepay known future expenses, (4) invest the remainder.
What Are Sinking Funds?
A sinking fund is money you set aside each month for a known future expense. Instead of being blindsided by a £600 car service or a £1,200 holiday, you save £50 or £100 per month throughout the year. The "shock" disappears.
Holiday
£100/mo
= £1,200/yr
Christmas / Gifts
£50/mo
= £600/yr
Car MOT/Service
£30/mo
= £360/yr
Home Maintenance
£100/mo
= £1,200/yr
Clothing & Shoes
£40/mo
= £480/yr
Pet Vet Bills
£50/mo
= £600/yr
Annual Insurance
£70/mo
= £840/yr
Tech / Devices
£30/mo
= £360/yr
5 Rules That Actually Work
Pay yourself first
Set up a standing order on payday to move savings before you can spend them. Savings you never see, you never miss.
Track for 30 days before setting targets
Budgets built on assumptions fail. One month of honest tracking reveals where money actually goes — usually not where you think.
Audit subscriptions quarterly
Most people have £50–£150/month in subscriptions they've forgotten. Review bank statements every 3 months and cancel anything unused.
Round up debt payments
If your minimum is £47, pay £50 or £60. Small round-ups dramatically accelerate payoff and require almost no willpower.
Review and adjust every month
A budget isn't a set-and-forget document. Life changes — income, expenses, goals. A 15-minute monthly review keeps you on track.
M Singh CeMAP DipFA · 25+ Years UK Financial Services
Important Information
This calculator is for informational purposes only and does not constitute financial advice or a personal recommendation.
Results are estimates based on the information you provide and may not reflect your actual financial position.
You should consider seeking independent professional advice tailored to your specific circumstances before making any financial decision.