📐 Practical guide · 5 min read

The 50/30/20 Rule:
how to budget
your salary

The simplest method to stop running out of money before month-end. Split your take-home pay into three buckets — needs, wants, savings — and it works at any income level.

5 minTo calculate your 50/30/20 and set up categories.
3 bucketsNeeds · Wants · Savings. Everything else is detail.
Freemigj applies the rule automatically to your real spending.

What is the 50/30/20 rule?

The 50/30/20 rule is a budgeting method popularised by economist Elizabeth Warren in the book All Your Worth (2005). The idea is brutally simple: split your take-home pay into three fixed-percentage blocks and assign each one a clear purpose.

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50% Needs

Everything you cannot cut: rent or mortgage, bills, groceries, transport, insurance, medicines. Stop paying these and you have a serious problem.

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30% Wants

Everything you want but don't strictly need: restaurants, streaming, non-essential clothing, hobbies, travel, gym. You could reduce these if necessary.

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20% Savings

Emergency fund, investments, pension, extra debt repayment. This slice goes out first — before you spend anything else. Not from the leftovers.

Calculate it for your income

Always base the calculation on your monthly take-home pay — what actually hits your bank account, not your gross salary. If you have variable income, use your 6-month average.

Take-home pay 50% Needs 30% Wants 20% Savings
£ / € 1,200 / mo600360240
£ / € 1,500 / mo750450300
£ / € 2,000 / mo1,000600400
£ / € 2,500 / mo1,250750500
£ / € 3,000 / mo1,500900600
£ / € 3,500 / mo1,7501,050700
£ / € 4,000 / mo2,0001,200800
£ / € 5,000 / mo2,5001,5001,000

💡 Household? Use your combined take-home

If you live with a partner or family, add up all net monthly incomes and apply the rule to the combined total. Alternatively, each person applies the rule to their own salary and you consolidate shared expenses separately.

How to apply it in 5 steps

  1. Find your monthly take-homeLook at what lands in your bank account, not your gross salary. If you have multiple income sources, add them all together.
  2. List your fixed needsRent/mortgage, bills, transport pass, groceries, insurance. These barely change month to month. If they already exceed 50% of take-home, you need to act on them — not on your lattes.
  3. Set your wants budgetRestaurants, bars, streaming, clothing, weekends away, hobbies. The 30% cap isn't punishment — it's a guaranteed guilt-free allowance for enjoying your life.
  4. Automate your savingsSet up an automatic transfer on the day after your salary hits. The 20% goes to a separate account before you even see it. This single habit separates consistent savers from everyone else.
  5. Track and adjust monthlyCompare actual spending vs targets. If needs blow past 50%, find what's hiding there. If wants stay under 30%, spend that margin — it's yours.

Real example: Alex and Sam, £3,000 take-home

Alex (£1,800 take-home) and Sam (£1,200 take-home) live together in London. Combined: £3,000/month.

CategoryBucketBudgetNotes
RentNeed£ 1,05035% of take-home — shared London flat
GroceriesNeed£ 300~£75/week for two
Bills + internetNeed£ 120Gas, electricity, water, broadband
TransportNeed£ 130Monthly passes × 2
Total needs£ 1,600~53% — slightly over, common in London
Restaurants & barsWant£ 250~2–3 meals out per week
ClothingWant£ 100£50 each
Streaming + hobbiesWant£ 150Netflix, gym, books
Travel savingsWant£ 200Set aside monthly for trips
Total wants£ 700~23% — under target, 7% flex
Emergency fundSaving£ 400Target: 6 months of expenses
ISA / investmentsSaving£ 300Monthly index fund contribution
Total savings£ 700~23% — above target ✓

When 50/30/20 doesn't work (and how to adapt it)

The rule is an excellent starting point, but it's not dogma. Here's when you need to adapt it.

📍 High-rent cities (London, Dublin, Amsterdam)

If rent alone is 40–45% of take-home, needs will exceed 50%. Adapt to 60/20/20 temporarily and work on reducing housing costs (flatmate, different area, buying).

💳 Existing debt

If you're repaying high-interest loans or credit cards, redirect part of the 20% to extra repayment. Clear expensive debt first, then invest.

👶 Young children

Childcare, nursery, and school supplies inflate needs. Consider 55–60% needs temporarily and reduce wants, not savings.

💶 Lower incomes (< £/€1,200/mo)

At lower incomes, 50% may not cover real needs. Use the rule as a direction, not a current reality — it shows you what to work towards.

How migj helps you apply the 50/30/20 rule

Knowing the rule is easy. Applying it every month with real spending data is the hard part. migj does it automatically.

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Import CSV from your bank

Download the CSV from your bank account and import it into migj. Transactions are categorised automatically — needs, wants, savings.

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Live 50/30/20 dashboard

See instantly where you stand vs targets. If wants exceed 30%, the bar turns red — mid-month, while you can still course-correct.

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Per-category budgets

Set a cap for each category (restaurants, clothing, hobbies). migj alerts you at 80% — you can still adjust before you blow the budget.

50/30/20 rule — frequently asked questions

Always net — what actually arrives in your bank account after taxes and deductions. Tax was never yours to spend, so don't include it. If you have variable income, use your 6-month average as the base.
A want, in most cases. If you stopped paying it, you wouldn't face a housing or food crisis. That said, the need/want split isn't moral — it's practical. If you'd cut everything before cutting the gym, that's valuable information about your priorities. Just be honest with yourself.
Compulsory state pension contributions are already deducted before take-home, so they don't appear in your calculation. Voluntary pension contributions (workplace top-ups, SIPPs, private pension payments) go into the 20% savings bucket.
Very common, especially in high-rent cities. First, track all spending for a full month — you'll often find "needs" that are actually disguised wants. If genuine needs genuinely exceed 50%, adjust the ratio (60/20/20) and focus on reducing housing costs over time rather than cutting essentials.
Yes. You can either apply it to the combined household income (one shared budget), or each person applies it individually to their own salary and you reconcile shared expenses. migj supports both approaches — shared budget for joint needs, individual budgets for personal wants.
Treat windfalls separately from monthly budgeting. A common approach: 50% to savings/debt, 30% to a specific goal (holiday, home), 20% to guilt-free spending. Don't inflate your monthly baseline based on irregular income you can't count on.

Apply the 50/30/20 rule to your real spending

Import your bank CSV. migj categorises automatically and shows where you stand vs targets.

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