A KfW student loan of 650 euros a month sounds like a clear sum, but the repayment depends on the term, the grace period and the interest rate. This guide works through an example step by step and says openly where the calculation is a simplification. The figures come from the KfW leaflet and the KfW interest announcement, status October 2026.
Short answer: At 650 euros a month over 36 months, the payout is 23,400 euros. The effective annual interest rate is 6.38 percent (status 1 October 2026, KfW). Repayment starts after a grace period of 18 to 23 months (KfW leaflet, status November 2023). The exact repayment total follows from the repayment schedule.
Key points
- The KfW student loan can be drawn at between 100 and 650 euros a month (KfW leaflet, status November 2023).
- At 650 euros a month, the maximum over the full term of 14 semesters is 54,600 euros.
- The effective annual rate from 1 October 2026 is 6.38 percent, and it is adjusted every six months.
- Repayment starts after a grace period of 18 to 23 months.
- Without a repayment schedule, the total repayment cannot be stated reliably.
What does 650 euros a month add up to over the term?
Assumption: you receive 650 euros a month for 36 months. That equals six semesters. The payout total is therefore 650 times 36, which is 23,400 euros.
| Item | Amount | Note |
|---|---|---|
| Monthly payout | 650 euros | Maximum amount in the leaflet |
| Payout period in the example | 36 months | Assumption, six semesters |
| Payout total in the example | 23,400 euros | 650 times 36 |
| Maximum total over 14 semesters | 54,600 euros | 650 times 84 months |
| Effective annual interest rate | 6.38 percent | Status 1 October 2026, KfW |
The total is the basis, but not the repayment. The loan is paid out, accrues interest and is repaid later. The interest estimate further down gives only an order of magnitude.
How long is the loan paid out, and which scale applies?
The possible funding period depends on your age. The leaflet sets it in steps, with more semesters for younger students. The table below calculates the maximum sum for the monthly amount of 650 euros.
| Age at start | Funding period | Maximum at 650 euros a month |
|---|---|---|
| up to 24 years | 14 semesters | 54,600 euros |
| up to 34 years | 10 semesters | 39,000 euros |
| up to 44 years | 6 semesters | 23,400 euros |
The scale comes from the leaflet, status November 2023. The KfW product page could not be retrieved when this guide was researched, so check that the conditions still apply before you apply.
How high is the interest, and what does it mean for the example?
According to KfW, the effective annual rate has been 6.38 percent since 1 October 2026, before that 6.53 percent. KfW adjusts the rate every six months, on 1 April and 1 October, and the next adjustment is planned for 1 April 2027 (KfW announcement, status October 2026).
Assumption: the full 23,400 euros were paid out at once and accrued interest from the start. Then roughly 1,493 euros of interest would arise in the first year (23,400 times 6.38 percent), which is about 124 euros a month. This is a simplified upper bound, because in reality the balance grows step by step during payout, and the effective rate does not replace a calculation based on the repayment schedule.
When does repayment start?
According to the leaflet, the grace period lasts 18 to 23 months. During this time you do not yet have to repay the loan. Interest can still accrue during this phase, so check the current rules in your contract. Repayment runs for at most 25 years or until age 67. A minimum instalment also applies, and its amount is stated in the contract.
If you want to compare several offers, see Studienkredite im Vergleich: Kriterien und Stand 2026 (in German), which covers interest, payout and repayment across providers.
How do longer terms change the picture?
Assumption: the 6.38 percent rate applies all year, and the full amount is paid out from the start. The table shows how interest in the first year grows with the term.
| Term in the example | Payout total | Interest in the first year (assumption) |
|---|---|---|
| 36 months, 6 semesters | 23,400 euros | about 1,493 euros |
| 60 months, 10 semesters | 39,000 euros | about 2,488 euros |
| 84 months, 14 semesters | 54,600 euros | about 3,483 euros |
Longer terms mean more capital on which interest accrues. If you draw only the amount you need, you pay correspondingly less interest, even if the maximum remains available.
How can you estimate the interest yourself?
- Multiply the monthly amount by the number of months to get the payout total.
- Divide the annual rate by 100, which gives 0.0638 for 6.38 percent.
- Multiply the payout total by this factor to get the interest for one full year.
- Divide the result by 12 to get a rough monthly burden.
This is a rough estimate. It ignores compound interest and the timing of the payouts.
Why this calculation is only an order of magnitude
Three factors determine the real repayment: the actual payout schedule, how interest is calculated during payout and grace period, and the repayment rate you agree to. The interest in the example is therefore not a forecast. It only shows the scale of interest on a large amount.
Frequently asked questions
How much do I have to repay in total?
That depends on the payout total, interest, grace period and repayment rate. Without a repayment schedule, the total cannot be stated reliably. Ask for the schedule before you sign and check it with your own assumptions.
Can I choose the monthly amount freely?
According to the leaflet, the payout amount lies between 100 and 650 euros a month. The repayment rate that fits depends on the contract and the schedule. The higher the monthly amount, the faster the sum you later have to repay grows.
How much does the interest rate change?
The rate is adjusted every six months, on 1 April and 1 October. On 1 October 2026 it was 6.38 percent, before that 6.53 percent. Plan with a buffer rather than with the rate of a single day.
What exactly is the grace period?
The grace period is the time during which you do not yet have to repay the loan. According to the leaflet, it lasts between 18 and 23 months. Which length applies to you depends on the terms of your contract, so check the current documents.
What to do next
- Set the monthly amount and the number of months you actually need.
- Calculate the payout total and check whether it fits the scale for your age.
- Request the repayment schedule and recalculate interest with the current rate.
- Compare the offer with other student loans before you sign the contract.
Related guides
- Student loan comparison 2026: KfW, education funds and banks (in German)
- KfW student loan 2026: interest, payout and repayment (in German)
- Bildungskredit: application, interest and repayment 2026 (in German)
- Studying over 30: financing with BAföG, grants and loans
Sources: KfW leaflet on the student loan (status November 2023); KfW questions and answers on the student loan (status October 2026)
Last updated: October 2026. This guide is general information, not individual advice.
