Estimate monthly mortgage repayments
Use the Mortgage Repayment Calculator to compare repayments, interest, and overpayment scenarios.
Quick answer
- Fixed rates keep repayments fixed for a set period.
- Variable rates can change, so repayments can rise or fall.
- Fixed rates may have early repayment or switching restrictions.
- The best choice depends on certainty, flexibility, rate level and risk tolerance.
On this page
Fixed rate repayments
With a fixed rate, your interest rate and monthly repayment stay the same for the fixed-rate period. This can make budgeting easier because you know what you will repay each month during that period.
Variable rate repayments
With a variable rate, your lender can change the rate. If the rate goes up, your repayment can increase. If it goes down, your repayment may reduce. Variable rates may offer more flexibility, but with less certainty.
Comparison table
| Area | Fixed rate | Variable rate |
|---|---|---|
| Monthly certainty | Higher during fixed period | Lower, rate can change |
| Overpayments | May be limited or charged | Often more flexible |
| Switching | May have break fee | Usually easier |
| Rate drops | You may not benefit during fixed period | Repayment may reduce if lender cuts rate |
| Rate rises | Protected during fixed period | Repayment may rise |
How to compare them with a calculator
Run the same mortgage amount and term with different rates. Then compare not only the monthly repayment, but also the total interest and what happens if the rate changes after the fixed period.
Frequently asked questions
Is fixed better than variable?
Not always. Fixed can give certainty, while variable can give flexibility. The right choice depends on your circumstances and market rates.
Can I switch from fixed to variable?
Possibly, but a fixed-rate mortgage may have a break fee or conditions.
Can variable repayments go up?
Yes. If the lender increases the variable rate, the monthly repayment can rise.
Why do people choose fixed rates?
Many choose fixed rates for budgeting certainty and protection from rate rises during the fixed period.
Can I overpay on a fixed mortgage?
Sometimes, but limits or fees may apply. Check your mortgage terms.
Is this guide tax advice?
No. It is general information for planning. Use official guidance or a tax adviser for your own situation.
Can I use the calculator for filing?
Use it as an estimate only. Complex activity such as DeFi, staking, mining, business trading, or many swaps may need specialist software or advice.
Sources & references
Key takeaways
- Fixed rates are useful for repayment certainty.
- Variable rates can change and may offer flexibility.
- Overpayment and switching rules matter.
- Compare both monthly repayment and total cost.