How this is calculated
ratio = monthly rent ÷ (yearly income ÷ 12) × 100; guideline rent = monthly income × 30%
The rent-to-income ratio divides your monthly rent by your gross monthly income. The famous 30% guideline traces back to US housing policy from the 1980s: households paying more than 30% of income on housing are classified as 'cost-burdened', and above 50% as 'severely cost-burdened'. Landlords apply the same math in reverse when they require income of 3× the rent.
Like all rules of thumb, it bends with context. High earners can healthily exceed 30% because their remaining 70% is plenty; in expensive cities, median renters routinely pay 35-45% not by choice but by market. Meanwhile someone with heavy student debt or childcare costs may feel squeezed even at 25%. The ratio is a smoke detector, not a verdict.
The most useful number here is often the third one: the income a rent 'requires' under the guideline. It converts apartment listings into salary terms while you browse — a $2,000 listing is an '$80,000 apartment' — which makes overreach visible before the lease is signed, not after.
Frequently asked questions
Gross or net income?
The 30% guideline uses gross (pre-tax) income, and so do landlord screenings. If you prefer the conservative view, run it with net income — then a 40% gross-style threshold is the rough equivalent.
Does the 30% include utilities?
Officially, housing-cost burden counts rent plus essential utilities. If your utilities run high, add them to the rent input for the truthful ratio.
What if my ratio is above 40%?
You're in territory where housing crowds out saving and shock absorption. The levers are the usual hard ones — roommates, a longer commute, negotiating renewal, or income growth — but knowing the number precisely is the first honest step.
Do landlords really require 3× rent?
Very commonly in the US, yes — it's the same 30% rule expressed as an income multiple. Some accept guarantors or larger deposits instead.