17 January 2026·7 min read

Rent-to-Income Ratio Explained: What Percentage of Income Should Go to Rent?

Your rent-to-income ratio determines whether housing is genuinely affordable. Here's how to calculate it, what's considered healthy, and how it varies by city.

Your rent-to-income ratio is one number that tells you more about your housing situation than almost any other metric. Calculate it wrong, or ignore it entirely, and you risk spending years in financial stress without understanding why.

This guide explains what the ratio is, how to calculate it correctly, what different thresholds actually mean, and how the numbers shift depending on where you live.

What Is Rent-to-Income Ratio?

The rent-to-income ratio (RTI) is the percentage of your gross monthly income that goes toward rent. It's calculated as:

RTI = (Monthly Rent ÷ Gross Monthly Income) × 100

So if you earn £3,500/month gross and pay £1,050 in rent, your RTI is 30%.

Simple. But the interpretation is where most people go wrong.

The 30% Rule — and Why It's Misleading

The most quoted benchmark is the "30% rule": spend no more than 30% of gross income on rent. This threshold comes from the US Housing Act of 1969, which defined housing as "affordable" if it cost less than 25% of income — later revised upward to 30%.

The problem? It was designed for a different era, different tax rates, and a different cost of living structure. Using gross income is particularly misleading because what you actually have to spend is your net income — after tax, national insurance or social security, and pension contributions.

A software engineer earning £80,000 in London pays roughly 32% in effective taxes. Their gross monthly income is £6,667, but net is around £4,533. At 30% of gross, they'd spend £2,000/month on rent — which is 44% of their actual take-home. That's not comfortable by any measure.

The fix: always calculate RTI against net income.

Gross Salary	Net Monthly (UK)	30% of Gross	% of Net
£30,000	£1,983	£750	38%
£45,000	£2,825	£1,125	40%
£60,000	£3,533	£1,500	42%
£80,000	£4,533	£2,000	44%

The higher your salary, the more the gross-based rule overestimates what you can afford. For high earners in high-tax countries, the 30% rule can leave you genuinely stretched.

The Net-Based Rent Tiers

A more useful framework uses net income:

RTI (Net)	Verdict	What It Means
Under 25%	Comfortable	Strong buffer for savings, emergencies, lifestyle
25–33%	Manageable	Liveable but limited flexibility
33–40%	Stretched	Possible short-term, difficult to build savings
Over 40%	Unaffordable	Housing is consuming too much — review urgently

These bands hold across most markets, though the comfortable threshold shifts in high-cost cities where 35% net is often considered acceptable given the career and lifestyle upside.

How to Calculate Your Own Ratio

Find your net monthly income — take-home after all deductions. If you're paid annually, divide by 12.
Find your total housing cost — rent plus any obligatory service charges or fees included in your lease. Don't include utilities unless they're fixed in the contract.
Divide and multiply: (housing cost ÷ net monthly) × 100

Use SpendVerdict's rent calculator to get an instant verdict — it runs this calculation automatically and benchmarks your ratio against real data for your city.

Rent-to-Income Ratios by City (2026)

The same ratio hits differently depending on where you live. Cities with higher salaries often have higher rents too — the ratio is what reveals whether the premium is worth it.

City	Typical 1-Bed Rent	Median Net Monthly	Median RTI
London	£2,100	£2,800	75%
Amsterdam	€1,700	€2,900	59%
Paris	€1,400	€2,400	58%
Barcelona	€1,200	€2,000	60%
Berlin	€1,300	€2,600	50%
Dublin	€2,000	€2,800	71%
Lisbon	€1,400	€1,600	88%

These are median figures — meaning half the population in each city is paying above these ratios. In London and Lisbon, the median renter is by any standard definition housing-cost-burdened.

The takeaway: a healthy RTI isn't just about your choices. In some cities, achieving a sub-30% ratio on a median income is genuinely impossible. This matters for how you plan your finances and career.

RTI and Savings Rate: The Trade-off

Housing spend and savings rate are directly connected. Every extra percentage point of income going to rent is a percentage point that can't go to an emergency fund, pension, or investment.

A useful benchmark: aim to save at least 15-20% of net income. If your RTI plus savings target exceeds 100%, something has to give — either the rent, the savings rate, or you need to increase income.

Net Monthly	Comfortable Rent (25%)	Max Rent + 15% Savings	Remaining for Everything Else
€2,000	€500	€700 + €300 savings	€1,000
€3,000	€750	€1,050 + €450 savings	€1,500
€4,000	€1,000	€1,400 + €600 savings	€2,000
€5,000	€1,250	€1,750 + €750 savings	€2,500

When a High RTI Is Acceptable

A high rent-to-income ratio isn't always a disaster. Context matters:

You're early in your career in a high-value city. Paying 45% of net for a few years in London or Amsterdam can be rational if it accelerates earnings faster than the cost.
Your income is growing fast. If salary increases will drop the ratio significantly within 12–18 months, the stretch may be short-term.
Low other fixed costs. No car, no debt repayments, low food costs — your overall financial picture may be healthy despite high rent.
Temporary situation. Saving to buy, or in a transitional period, high rent may be a calculated short-term choice.

What makes a high RTI dangerous is when it's permanent, unplanned, and crowding out savings. If you've been at 45%+ for three years with no plan to change it, that's the warning signal.

Reducing Your Rent-to-Income Ratio

If your RTI is uncomfortably high, the levers are:

Reduce rent:

Move to a cheaper neighbourhood (check city-by-city data on SpendVerdict)
Get a flatmate — splitting a two-bed is almost always cheaper than a one-bed alone
Negotiate at renewal — especially if you're a reliable tenant

Increase income:

Ask for a raise benchmarked against market data
Add freelance income or a side project
Switch employers — job moves typically yield 15–25% salary jumps vs 3–5% for internal raises

Hybrid:

Remote-work to a cheaper city while keeping the same salary is one of the most powerful levers available to knowledge workers right now. Living in Berlin or Lisbon on a London salary produces dramatically different RTI numbers.

FAQ

Does RTI include utilities? Standard RTI calculations use rent only. For total housing cost burden, add fixed utilities — but keep the two figures separate so you can compare against benchmarks.

What if I'm self-employed with variable income? Use your average monthly net income over the last 12 months, not your best month. Build a 20% buffer.

Is RTI the same as the debt-to-income ratio? No. Debt-to-income (DTI) includes all debt repayments — loans, credit cards, rent. RTI is rent only. Lenders use DTI for mortgage applications; RTI is a personal planning tool.

What's a good RTI to target before buying? Getting to sub-25% RTI on rent generally means you have enough financial cushion to also service a mortgage. It's a useful proxy for mortgage readiness.