Fixed-cost ratio (Fixkostenquote)

Level 3 · Advanced

German termFixkostenquote

Read firstConsumption floor · Gross vs. net income · Percentages and shares

Used byGerman cost benchmarks (rent ratios etc.)

Deep divesBudgeting Methods

The fixed-cost ratio (Fixkostenquote) is the share of net income that fixed, recurring obligations consume — rent, insurance premiums, loan installments, and subscriptions — expressed as a percentage. Dividing total fixed costs by net income and multiplying by 100 turns a scattered list of individual bills into a single number that stays comparable across households and cities.

Why it matters

A fixed-cost ratio of 45% means the same thing whether net income is €2,000 or €5,000 a month, while a raw euro total does not — €900 in fixed costs is tight for one household and trivial for another. Budgeting frameworks that target a ceiling on fixed costs (commonly around half of net income) use this ratio, not the euro figure, because a lower ratio leaves more room to absorb an income drop without renegotiating rent, insurance, or loan terms. City cost-of-living comparisons rely on the same ratio to show how affordability differs across German cities independent of local salary levels — a city where wages and rent both run high can still carry a lower fixed-cost ratio than a cheaper city with lower wages.

Worked examples

1. Computing the ratio for one household. Net income (Nettoeinkommen, after tax and social insurance) is €3,000/month. Fixed obligations: Kaltmiete (cold rent, excluding utilities) €900, Nebenkosten (utility and building cost advance payments) €200, health insurance contribution €250, liability and household insurance €35, and a phone/internet contract €40. Total fixed costs: €900 + €200 + €250 + €35 + €40 = €1,425. The fixed-cost ratio is €1,425 / €3,000 = 0.475 = 47.5% — just under half of net income goes to obligations that cannot be adjusted month to month.

2. Comparing two households across cities. The ratio exposes affordability differences that raw rent or income figures hide on their own.

Household	Net income	Fixed costs	Fixed-cost ratio
A — smaller city	€2,400	€1,080	45%
B — expensive metro	€3,600	€2,160	60%

Household B earns €1,200 more per month than Household A, but a larger share of that income is already committed before any spending decision is made. Household A has a smaller income but more of it remains flexible — 55% versus 40% for Household B. Comparing the two euro incomes alone would suggest B is simply better off; the ratio shows B has less room to maneuver if income drops or an unexpected cost appears.

Check yourself

A household has net income of €2,500/month. Fixed costs: rent €700, utilities €150, insurance €200, phone/internet €40. What is the fixed-cost ratio, as a percentage?

A household's fixed-cost ratio is 38%. What does this figure describe?

The household spends exactly €380 on fixed costs every month38% of net income goes to fixed, recurring obligations38% of the household's spending is optional, flexible spendingThe household saves 38% of its net income

Person A calculates their fixed-cost ratio using gross salary (before tax and social insurance) as the denominator. Person B uses net income (after tax and social insurance). Both have identical fixed costs and identical gross salary. What happens to Person A's ratio compared to Person B's?

A's ratio comes out higher than B's, because gross salary is the larger figureA's ratio comes out lower than B's, understating how tight the fixed costs actually are relative to spendable incomeThe two calculations produce the same ratio, since the fixed costs themselves are unchangedIt's impossible to say without knowing the exact tax rate

A household earns €3,000/month net and has €1,650/month in fixed costs. What percentage of net income remains flexible, i.e. not committed to fixed costs?