Proportional split vs 50/50 (UK): which is fairer?
Proportional splits optimize for balanced leftovers; 50/50 optimizes for symmetry and simplicity. This page compares both using the same household numbers so you can see the trade‑off clearly.
Prefer to start from the hub? Open the main calculator.
Calculator
Worked examples
Each example uses the same calculator engine. Use “Open in calculator” to share or compare scenarios.
Same home, compare proportional vs 50/50
Incomes: A £3,100 · B £2,200
Shared total: £2,807 / month
Split (proportional): A £1,642 · B £1,165 · Leftovers: A £1,458 · B £1,035
Push the same scenario to 50/50
Incomes: A £3,100 · B £2,200
Shared total: £2,807 / month
Split (equal): A £1,404 · B £1,404 · Leftovers: A £1,696 · B £796
FAQ
Why do leftovers matter more than “fair percentages”?
Because your day‑to‑day life is funded by leftover money. A split that leaves one person with very little leftover often creates friction, even if the percentages look reasonable.
When does 50/50 work well?
When take‑home pay is similar, or when you both strongly prefer symmetry and can still hit savings goals comfortably under 50/50.
Can we do a hybrid approach?
Yes. Many couples split core housing costs proportionally, but handle discretionary spending separately. You can also use a custom split like 60/40 or 66/34 if it’s easier to maintain.
Related links
- Open the main calculator (hub)
- Fair splits: proportional vs 50/50 vs custom
- Stress test: rate rises + one-income
- How it works (formulas and methodology)
- 66/33 vs 50/50 split (UK)
- Split mortgage by income (UK)
- Proportional bills split (UK)
- How much house can we afford? (UK)
- FAQ (assumptions and common questions)
Related guides
Mortgage & bills split calculator
Run your numbers live and share a scenario link.
50/50 vs proportional vs custom splits
Choose a split that feels fair and stays sustainable.
Split the mortgage by income (UK)
Proportional splits explained with worked examples.
Proportional bills split calculator guide
Turn take-home pay into a clean monthly split.
66/33 vs 50/50 split for couples
When a custom split beats proportional (and when it doesn’t).
Stamp Duty (SDLT) calculator for couples
Standard vs first-time buyer relief + surcharges.
60/40 bills split guide
A simple compromise between 50/50 and proportional.
70/30 bills split guide
When a fixed split makes sense (and how to validate it).
75/25 bills split guide
For very different incomes: keep leftovers and resilience in view.
Should we split the mortgage 50/50?
A simple decision framework using leftovers and stress tests.
Tip: open a guide in one tab and the calculator in another to compare options quickly.