You’ve probably heard the 30% rule: spend no more than 30% of your income on rent. It gets repeated everywhere, by landlords, letting agents, financial bloggers, your parents.
The problem is that in most cities where young people actually live, 30% of income doesn’t get you very far. Renters in London, New York, Los Angeles, and most other major cities regularly spend 40–50% of their income on housing. Either they’re all doing something wrong, or the rule is broken.
It’s mostly the rule.
Where the 30% rule came from
The 30% figure has a specific history. It traces back to US public housing policy in the 1960s, when federal housing assistance set rent contributions at 25% of tenant income. In 1981, that threshold was raised to 30% as part of budget cuts, a political decision, not a financial analysis. It stuck, and eventually got adopted as a general guideline for everyone.
The rule was designed in an era when housing costs were a smaller proportion of wages, cities were less expensive relative to incomes, and most people who rented were doing so because they hadn’t yet bought, not because buying was completely out of reach.
It’s also based on gross income, not what you actually take home. If you earn $50,000 a year in the US, 30% of gross works out to $1,250 a month. After federal income tax, state tax, and FICA, you might take home $3,300 a month. Spending $1,250 of that on rent is actually 38% of your net income.
In the UK, the mismatch is even starker. A London salary of £38,000 is roughly £2,500 a month after tax and National Insurance. The median rent for a one-bedroom flat in London hit around £2,000 a month in 2024. That’s 80% of take-home for a single person living alone, nowhere near any version of the 30% rule.
The rule needs to be used differently.
30% of what, exactly
The most useful version of the rule is based on net income, what actually lands in your account each month, not the number on your contract before tax.
Using net income also makes the maths honest. If you earn £2,800 a month after tax and your rent is £1,000, that’s 36% of your actual money. If you run the same calculation on gross income of £40,000, it looks like only 30%. But that’s not money you can spend.
A reasonable target for most people: housing costs shouldn’t consistently exceed 35% of your monthly net income. That gives more room than the old rule in a world where rents are higher, while still leaving enough for everything else to function.
That said, 35% is still just a starting point. Whether it works depends on what you earn, where you live, and what else you owe.
What rent actually costs (it’s more than the rent)
The monthly figure on your lease is only part of the cost of renting. Add everything together and the real number is usually 15–25% higher.
In the US, utilities (gas, electricity, water) are often paid separately from rent, adding $100–$200 a month depending on the apartment and climate. Internet runs another $50–$80. If the apartment doesn’t include parking and you have a car, add that too. Renter’s insurance is relatively cheap ($15–$25 a month) but worth counting.
In the UK, council tax is almost always on top of rent and varies by borough. In London it ranges from around £1,200 to £2,400+ a year depending on the band and borough. Gas, electricity, and internet add another £150–£250 a month on average. Buildings insurance is typically the landlord’s responsibility, but contents insurance is yours.
There’s also the cost of the commute. Moving one zone further out to save £200 a month in rent sounds good until you factor in the extra £80–£120 a month in transport costs, plus the time. It’s worth running the actual numbers before committing to somewhere cheaper but less convenient.
Cutting your monthly bills covers ways to reduce the non-rent costs, which can meaningfully change your all-in housing number.
How to figure out what you can actually afford
The question isn’t what percentage of income you should spend on rent in theory. It’s what figure works for your specific income, location, and financial situation.
Start with your monthly net income. From that, subtract your fixed non-negotiables in order:
First, debt repayments. If you have student loan payments, a car loan, or credit card minimums, these come out before housing is even on the table. In the US, the common guidance is to keep total debt payments (including housing) below 43% of gross income, the standard for most mortgage qualification rules, and it’s useful as a ceiling for renters too. In the UK, lenders typically want to see housing costs below 35–40% of gross income for mortgage applications, which gives a similar benchmark.
Second, savings. Before you decide what you can afford on rent, decide what you’re saving each month. If that’s not built into your budget first, it tends not to happen. Even 10% of net income set aside before calculating housing leaves you in a structurally different position a few years down the line. Building a monthly budget that puts savings first is the more reliable approach than hoping to save whatever’s left over.
Third, the basics: food, transport, phone, essential subscriptions. These are roughly fixed regardless of where you live.
Whatever’s left after debts, savings, and everyday essentials is your realistic housing budget. That’s the number to use, not 30% of your salary.
A simple example
Say you take home £2,600 a month in the UK:
- Student loan repayment: £150
- Savings (10%): £260
- Food, transport, phone, basics: £600
- Remaining: £1,590
If your all-in housing cost (rent + bills + council tax) is £1,200, that’s about 46% of take-home but leaves £390 for discretionary spending, which is tight but workable. If it’s £1,500, you’re left with £90 for everything else. That’s not a housing problem; that’s a maths problem that needs solving before you sign a lease.
Run the same exercise with your own numbers before you commit to anything.
When rent is taking too much
If you live somewhere where housing genuinely consumes most of your income, you’re not alone and you’re not doing it wrong. The market in many cities simply doesn’t work at the income levels most people in their 20s have.
House sharing is the most immediate lever. Sharing a two-bedroom flat in London typically costs 30–40% less than renting a one-bedroom alone. The maths often works even if you’d prefer privacy, and for most people in their 20s, the trade-off is worth it for a few years.
Negotiating rent is underused. Landlords in slow markets or with properties that have been empty a while will often take a lower offer, especially if you offer a longer lease term or early rent payment. It doesn’t always work, but asking costs nothing. The renting vs buying guide covers the broader picture of how long renting actually makes financial sense versus buying.
Moving further out only works if the commute cost and time are genuinely better after you account for transport. Run the numbers before deciding.
Increasing income is harder to action quickly but more durable. If your rent is consuming too much because your income is low, a salary increase, promotion, or side income changes the equation in a way that moving borough doesn’t. Negotiating your salary is worth reading before your next review.
Building toward a deposit is the longest-term option. If renting doesn’t work long-term where you want to live, saving for a house deposit explains how to make meaningful progress even while paying high rent.
The real number to watch
The 30% rule isn’t useless. It’s a useful check: if your rent is 20% of your net income, you’re probably fine. If it’s 55%, something has to give. The number in between is where real life happens.
Keep tabs on housing, debt repayment, and savings together rather than obsessing over any one percentage. If all three are getting funded, the exact split matters less than you think. If one of them is being starved to cover the others, that’s the problem to solve.
What you spend on rent is only part of the picture. What you keep, and what you do with it, is the rest. Letting housing costs creep up as income grows is one of the most common ways lifestyle creep takes hold, worth keeping an eye on as your earnings increase.