When you take out a loan, one of the first choices you'll face is fixed versus floating (also called variable) interest. It's a genuine tradeoff, not a settled question — the right answer depends on what you value and how much risk you can tolerate.
Fixed rate: predictability, at a price
A fixed interest rate stays exactly the same for the entire loan term. Your payment never changes, which makes budgeting simple and protects you completely from rising interest rates. The tradeoff: fixed rates are usually set somewhat higher than a starting floating rate, since the lender is pricing in the risk that rates could rise over the loan's life and they're locked into today's rate regardless.
Floating rate: potentially cheaper, genuinely uncertain
A floating rate moves with the broader market — commonly tied to a benchmark rate that adjusts periodically. If market rates fall, your payment can fall with it. If they rise, so does your payment, sometimes substantially. Floating rates often start lower than fixed rates for an equivalent loan, which is the appeal — but that starting rate is not a guarantee of what you'll pay two or five years in.
How to actually decide
A few genuine signals worth weighing:
- How long you'll hold the loan. The shorter your expected time with the loan (for example, planning to sell a home or refinance within a few years), the less time a floating rate has to work against you — this favors floating for short holds and fixed for long ones.
- Your tolerance for payment uncertainty. If a meaningfully higher payment would strain your budget, that's a strong argument for fixed, regardless of the math — certainty has real value beyond what a rate comparison captures.
- The current rate environment. When floating rates are only marginally lower than fixed, the potential savings often aren't worth the added risk. When the gap is large, floating becomes more tempting — but large gaps usually exist because the market expects rates to move.
Where this fits with our calculators
Our loan calculator and mortgage calculator both model fixed-rate loans, since that's the calculation that has one clean, predictable answer — a floating-rate loan's total cost depends on a rate path nobody can know in advance, which is a projection exercise rather than a fixed calculation. If you're weighing a floating-rate offer, one practical approach is to run the fixed-rate math at a couple of possible future rates using our calculator, to see the range of what you might actually pay rather than just the teaser rate. For the savings side of the equation — what a rate difference is worth over time if invested instead — our compound interest calculator can help put a number on it.