Pay in Full vs Interest-Free Instalments
Paying in full saves price × discount. Deferring lets the money sit in savings, but the balance falls each month so the average is half the principal and the interest is halved too. Compare the two figures.
Your numbers
Difference
42,000
Saved
60,000
Interest
18,000
Monthly payment
100,000
What it means
Paying in full wins by 42000.
Formula
Difference = Price × Percentage ÷ 100 − Price × Annual rate ÷ 100 × Instalments ÷ 24
If interest-free instalments forfeit cashback or points, subtract that from the interest side. Also check whether the instalments crowd out next month’s spending.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| PriceThe amount being charged. Decide first whether it is before or after tax. | 1,200,000 | 0 and up |
| Percentage (%)A share expressed out of 100. | 5 | 0 ~ 100 |
| Instalments (mo)How many months to spread it over; longer means more fee in total. | 12 | 1 ~ 60 |
| Annual rate (%)Interest quoted per year; the monthly rate is this over 12. | 3 | 0 ~ 30 |
Step by step
Quick reference table
Results when only Price changes and everything else stays put.
| Price | Difference | Saved | Interest |
|---|---|---|---|
| 600,000 | 21,000 | 30,000 | 9,000 |
| 900,000 | 31,500 | 45,000 | 13,500 |
| 1,200,000 | 42,000 | 60,000 | 18,000 |
| 1,800,000 | 63,000 | 90,000 | 27,000 |
| 2,400,000 | 84,000 | 120,000 | 36,000 |
What each result means
| Result | At default values |
|---|---|
| DifferenceThe gap between two values — a quantity, not a rate. | 42,000 |
| SavedHow much this deal keeps in your pocket. | 60,000 |
| InterestThe interest earned or owed over the period. | 18,000 |
| Monthly paymentWhat you owe every month. | 100,000 |
Common mistakes
If interest-free instalments forfeit cashback or points, subtract that from the interest side. Also check whether the instalments crowd out next month’s spending.
Glossary
- Price
- The amount being charged. Decide first whether it is before or after tax.
- Percentage
- A share expressed out of 100.
- Instalments
- How many months to spread it over; longer means more fee in total.
- Annual rate
- Interest quoted per year; the monthly rate is this over 12.
- Difference
- The gap between two values — a quantity, not a rate.
- Saved
- How much this deal keeps in your pocket.
- Interest
- The interest earned or owed over the period.
- Monthly payment
- What you owe every month.
Frequently asked questions
QHow is Pay in Full vs Interest-Free Instalments calculated?
Difference = Price × Percentage ÷ 100 − Price × Annual rate ÷ 100 × Instalments ÷ 24 — Paying in full saves price × discount. Deferring lets the money sit in savings, but the balance falls each month so the average is half the principal and the interest is halved too. Compare the two figures.
QCan you walk through an example?
With Price 1,200,000, Percentage 5%, Instalments 12mo, Annual rate 3%, the answer is Difference 42,000.
QWhat do I need to enter?
Enter Price, Percentage, Instalments, Annual rate. The result recalculates as you type, and an empty box counts as zero.
QHow much does the answer move if I change a number?
Changing only Price moves the answer to Price 600,000 → Difference 21,000 and Price 2,400,000 → Difference 84,000. The table below lays out five steps.
QHow are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
QAnything to watch out for?
If interest-free instalments forfeit cashback or points, subtract that from the interest side. Also check whether the instalments crowd out next month’s spending.
Related calculators
Tax rates and interest conventions differ by country and product — check your contract for real transactions.