The classic rule says rent should stay under 30% of gross income. Enter pay and see the ceiling, a more comfortable target, and the real share of any rent you are considering.
Landlords commonly require gross income of at least 3× the rent, which is the same as the 30% rule. It is a screening rule, not a budget: in high-cost areas many households exceed it, and with heavy debts even 30% can be too much. The "comfortable" figure below uses 25%, and the check mode shows any rent as a percentage of income so the trade-off is explicit.
Is the 30% rule based on gross or net pay? Gross (before tax) — that is how landlords apply it. Budgeting on take-home pay is stricter and safer.
What else should the budget leave room for? Utilities not included in rent, a deposit (often one month), moving costs, and an emergency cushion. A rent at 30% with no cushion is still tight.