Fixed vs. variable costs (Fixkosten vs. variable Kosten)

Level 1 · Basics

German termFixkosten vs. variable Kosten

Used byConsumption floor · Running costs · Budgeting frameworks (50/30/20 etc.) · Remittances as a fixed cost · Three-account structure (Floor / Future / Free) · Cold rent vs. warm rent · Sinking fund

Deep divesBudgeting Methods

A fixed cost is a recurring expense that stays the same amount each period regardless of behavior; a variable cost changes month to month based on choices or usage. Rent (Miete), insurance premiums, and loan installments are fixed. Groceries, transport, and entertainment are variable. The split matters because it shows how much of an income is already committed before a single spending decision gets made.

Why it matters

Every budgeting method — the 50/30/20 rule, zero-based budgeting, envelope systems — starts by separating what a household must pay regardless of the month from what it can adjust. A high fixed-cost base (rent, insurance, loan installments) leaves little room to absorb a bad month; a lower one gives more flexibility if income drops or a car repair shows up unannounced. This distinction also underlies how a Nebenkosten (utility cost) prepayment differs from the Kaltmiete (cold rent, excluding utilities) itself, why a sinking fund exists for irregular-but-predictable costs like an annual insurance bill, and why a remittance sent home might count as fixed (a standing family commitment) or variable (an occasional gift) depending on how it is set up.

Worked examples

1. Splitting a monthly budget. A household with €2,800 net monthly income lists its expenses:

Expense	Amount	Fixed or variable
Kaltmiete (cold rent)	€950	Fixed
Nebenkosten (utilities)	€180	Fixed (billed monthly, adjusts once a year)
Insurance premiums (Versicherungen)	€140	Fixed
Phone/internet contract	€45	Fixed
Groceries	€400	Variable
Transport (fuel, tickets)	€120	Variable
Restaurants and entertainment	€250	Variable

Fixed costs total €1,315 (about 47% of net income); variable costs total €770 (about 28%), leaving €715 (about 26%) for savings and debt repayment. Naming each line "fixed" or "variable" before assigning it a budget category shows immediately how much of the income has no month-to-month flexibility.

2. A cost that looks fixed but isn't. A gym membership billed at a flat €30/month is fixed in amount but discretionary in the sense that it can be cancelled with notice. A "fixed" cost is defined by whether the amount changes month to month, not by whether it is optional in principle. Car insurance is fixed and (mostly) non-discretionary; a subscription box is fixed and fully discretionary. Both are fixed costs for budgeting purposes because the euro amount does not move with day-to-day behavior — only the decision to keep or cancel the underlying commitment does.

Check yourself

A household has €3,200 net monthly income. Fixed costs: Kaltmiete (cold rent) €1,100, insurance premiums €160, loan installment €240. Variable costs: groceries €350, transport €90, entertainment €180. How many euros are left after all six of these expenses?

What actually makes a cost 'fixed' rather than 'variable'?

It cannot be cancelled or renegotiated under any circumstances.The euro amount stays the same from one period to the next, regardless of usage or behavior.It is a cost the household considers essential, as opposed to a luxury.

Which of these are variable costs? (Select all that apply.)

Groceries, which change in total each month based on what is bought.A car loan installment of a fixed euro amount due every month.Restaurant and entertainment spending, which rises or falls with choices made that month.A flat-rate phone and internet contract billed at the same amount every month.