In installment sales, correct calculation is the foundation of profit. A miscalculated monthly payment either causes a loss or scares the customer off. Below, we show how to calculate an installment payment schedule with an example.
The 4 Figures You Need for the Calculation
- Product price — for example, 6,000,000 UZS
- Down payment (initial payment) — for example, 1,000,000 UZS
- Term — how many months, for example 6 months
- Markup (profit percentage) — for example, 20%
The Core Formula
Installment amount = Price − Down payment
Total payment = Installment amount + (Installment amount × Markup%)
Monthly payment = Total payment ÷ Term
A Concrete Example
Let's suppose:
- Price: 6,000,000 UZS
- Down payment: 1,000,000 UZS
- Term: 6 months
- Markup: 20%
The calculation:
- Installment amount = 6,000,000 − 1,000,000 = 5,000,000 UZS
- Markup = 5,000,000 × 20% = 1,000,000 UZS
- Total payment = 5,000,000 + 1,000,000 = 6,000,000 UZS
- Monthly payment = 6,000,000 ÷ 6 = 1,000,000 UZS/month
So the customer pays a 1,000,000 UZS down payment and then pays 1,000,000 UZS each month for 6 months.
The customer's total outlay: down payment (1,000,000) + total payment (6,000,000) = 7,000,000 UZS. The cash price was 6,000,000 UZS — meaning the customer paid 1,000,000 UZS more for buying on installment. That extra amount is exactly your markup (your profit). The "total payment" (6,000,000) refers only to the portion paid in installments; the down payment is separate.
What Does the Payment Schedule Look Like?
| Month | Payment | Balance |
|---|---|---|
| 1 | 1,000,000 | 5,000,000 |
| 2 | 1,000,000 | 4,000,000 |
| 3 | 1,000,000 | 3,000,000 |
| 4 | 1,000,000 | 2,000,000 |
| 5 | 1,000,000 | 1,000,000 |
| 6 | 1,000,000 | 0 |
The Risk of Manual Calculation
Doing this calculation by hand or in Excel for every customer means time and errors. If the markup, term, or down payment changes, you have to recalculate. On top of that, when a payment comes in, updating the balance by hand gets forgotten.
A purpose-built system builds this schedule automatically, updates the balance after each payment, and flags delays.
Conclusion
Calculating a monthly installment payment is simple: subtract the down payment from the price, add the markup, and divide by the term. But when working with many contracts, manual calculation leads to errors — which is why it's better to use an automatic calculator and a payment schedule system.
Loome provides an installment calculator and an automatic payment schedule. Try it out →
Frequently asked questions
How is a monthly installment payment calculated?
The markup is added to (price − down payment), and the result is divided by the term (number of months).
How large should the markup be?
That depends on your profit strategy and the market. Many stores set it in the 15–30% range.
Can the payment schedule be built automatically?
Yes. Purpose-built installment software builds the schedule automatically from the amount, down payment, and term.