What does money cost that just sits there?
Commitment interest is charged on the part of your loan you have not yet drawn — once the interest-free period ends. On a build with monthly drawdowns over a year, several thousand euros add up quickly. This calculator uses exactly the engine from BOB’s funding view, month by month.
Updated: Pure contract arithmetic — your terms, no benchmarks
Stated in your loan contract
Also from the contract, e.g. 0.25%
How long your build draws the money bit by bit
Red: months with commitment interest on the undrawn amount. Negotiate longer free periods or plan drawdowns earlier.
How this calculator works
- 01
Your contract terms
Loan amount, interest-free months and monthly commitment rate are in your loan contract. The calculator takes them as they are — no benchmarks here, only your terms.
- 02
A drawdown plan like on site
The calculator spreads the drawdown evenly across your build time — a share each month, as progress invoices arrive. In BOB the same engine uses your real drawdown plan instead of the even spread.
- 03
Month by month on the remainder
After the free period: undrawn amount × monthly rate. The calculator sums this per month — you see which months are expensive and what earlier drawdowns or a longer free period save.
Calculation based on your contract terms with an even drawdown plan; your actual drawdown will differ. Not financing advice.
Frequently asked questions
Interest the bank charges on the not-yet-disbursed part of your loan — compensation for holding the money ready. It comes on top of the borrowing rate, starts after the interest-free period and ends once the loan is fully drawn.
The rate is in your contract; values around 0.25% per month are common in Germany — 3% a year, often less than early drawdown would cost in borrowing interest. More important than the rate is the free period: between 6 and 24 months much is negotiable.
Three levers: negotiate a longer free period (often for a small rate premium), plan the build schedule realistically — permit delays are the classic — and submit drawdowns promptly once invoices arrive. BOB’s funding tab shows when the next drawdown is due and which documents the bank needs.
Calculate both: expected commitment interest without the premium — versus the higher borrowing rate over the whole fixed period. For long builds (completion beyond 12 months) the longer free period often wins; for short projects rarely. This calculator gives you the first number to the month.
Yes, on different parts: borrowing interest on what is drawn, commitment interest on the rest. During the build both overlap — exactly why this double load belongs in the monthly liquidity plan BOB shows you.