Your KPR's Low Fixed Rate Isn't Permanent. Here's What Happens the Month It Switches to Floating
5 min read
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5 min read
You signed your KPR (home loan) because the monthly payment looked easy. Rp2.9 million a month for a Rp500 million loan. You planned your whole budget around it.
Then year three ends. The letter from the bank arrives. The new payment is Rp4.8 million.
Nothing went wrong. This is how a KPR fixed rate vs floating rate works. The low rate was never meant to last. This post shows exactly what changes, with real rupiah, so you can see the switch coming.
A fixed rate is an interest rate the bank promises not to change for a set time. Many Indonesian KPR products fix it for one to five years.
A floating rate (bunga mengambang) can change. After the fixed period ends, your loan moves to it automatically. The bank sets it based on market conditions, such as the central bank's benchmark rate and what it pays on deposits.
Banks also have a number called the SBDK (Suku Bunga Dasar Kredit, or base lending rate). Each bank publishes it. When your loan is floating, your rate follows the bank's rates at that time, so when they move, your payment can move too.
Here is the part people miss. The fixed rate is often a promotion. The floating rate is the bank's normal price.
Look at two numbers from 2026.
At the low end, BRI's KPR Solusi promotion ran until 30 June 2026. It offered fixed rates from 2.5% for the first year, and 3.45% for three years on loans of at least 10 years, according to reports in Kontan and Stockwatch.
At the high end, floating rates in August 2026 were far higher. Search reports of bank disclosures put BCA's KPR floating rate at 11%, Danamon's at 12.5% and CIMB Niaga's at 13.5%.
So a borrower can go from about 3.5% to about 11% or more. That is more than three times the rate. Bank Indonesia's benchmark rate, the BI-Rate, was held at 5.75% on 23 September 2026, so this gap is not just a rate move. It is the bank's promotion ending.
You can follow the BI-Rate and other rate data on the NetWort macro page.
Let's do the math. These numbers are an illustration, not a quote from any bank.
Step one. During the fixed period, the monthly payment is about Rp2.89 million.
Step two. After 36 payments, you still owe about Rp445 million. Only about Rp55 million of the loan is gone. Most early payments go to interest.
Step three. The remaining 17 years are now repriced at the floating rate. Here is what the new payment looks like:
| Floating rate | New monthly payment | Increase | Jump |
|---|---|---|---|
| 10% | Rp4.55 million | +Rp1.66 million | +57% |
| 11% | Rp4.83 million | +Rp1.94 million | +67% |
| 12.5% | Rp5.27 million | +Rp2.39 million | +83% |
All figures come from the standard loan payment formula, calculated by NetWort. They assume the rate stays flat after the switch and that no extra payments were made.
A one-point change matters too. Going from 11% to 12% adds about Rp293,000 a month on the same loan.
They budget against the promo. The first number a borrower sees is the fixed payment. It becomes the number in their head, even though it expires.
The balance barely moves. In the first years, most of each payment is interest. Your loan stays large, so the new rate applies to almost the whole amount.
Income does not rise by 60%. Payments can jump 50% or more. A raise of 5% to 10% a year does not close that gap.
Our mortgage debt-to-income post shows how to test whether a payment fits your income. Run that test on the floating payment, not the fixed one.
You have options, and the best time to use them is months before the date, not after.
The cushion in step five is the part you can start today. To know how big it can be, you need to know what you actually have.
Open your NetWort Dashboard and check your total portfolio value and how it is spread out. That tells you how much room you have if your KPR payment rises.