Loan Calculator
Calculate your monthly payment and total interest for any installment loan — personal, auto, student or home. Enter the loan amount, interest rate and term to see your repayment schedule totals.
How it works
M is the monthly payment, P the principal, r the monthly interest rate, and n the number of monthly payments. The formula calculates the fixed monthly payment needed to repay the loan with interest.
M = P · r(1+r)ⁿ ÷ ((1+r)ⁿ − 1)Worked examples
25,000 over 5 years at 7%
Juma, a car buyer in Mwanza financing 25,000 over five years.
A 25,000 auto loan at 7% for 5 years gives a monthly payment of about 495.03.
10,000 over 3 years at 12%
His brother Elias, borrowing less at a higher rate, to show what the rate does to the payment.
A 10,000 personal loan at 12% for 3 years gives a monthly payment of about 332.14.
A flat-rate quote on the same 10,000 loan
Elias, comparing a flat-rate quotation with the reducing-balance loan his brother was offered.
A 10,000 loan at a quoted 12% flat rate over 3 years charges 3,600 in interest on the full amount, giving a monthly payment of about 377.78. The reducing-balance loan above costs about 1,957 in interest over the same term, so two quotations that both say 12% are not the same deal.
What this assumes, and where it does not apply
What it assumes
- Equal monthly instalments on a reducing balance at the rate and term you enter.
- Interest is charged monthly on the balance outstanding, so the rate must be the monthly rate your lender quotes, not an annual figure divided by twelve.
- The quoted rate is applied to the balance still outstanding each month, so the interest charged falls as the loan is repaid rather than staying fixed on the original amount.
Where the result does not apply
- A flat-rate loan charges interest on the full amount for the whole term; compare total interest rather than the headline rate (see the loan interest guide).
- Excludes arrangement and processing fees, insurance, and any penalty for late or early payment.
- Does not model a payment holiday, a moratorium or an early settlement.
- A loan repaid in unequal amounts, such as a seasonal schedule for a farmer or a trader, will not follow the level payment this calculator produces.
Borrowing in Tanzania
The interest rate on a Tanzanian loan is usually quoted per month on a reducing balance, and the calculator above expects an annual figure — so multiply a quoted monthly rate by twelve before you enter it, and check which balance the rate is applied to. A flat rate is the trap: it is charged on the original amount for the whole term, so an apparently cheap headline rate costs considerably more than the same number on a reducing balance.
On a 10,000,000 TZS loan quoted at 12% over 3 years, a flat-rate lender charges 3,600,000 TZS in interest (377,778 TZS a month), while the same 12% on a reducing balance costs 1,957,152 TZS (332,143 TZS a month) — so the flat loan's true annual cost is about 21.2%, not 12%.
That example uses a 12% annual rate for illustration only. This site does not publish a “current Tanzanian loan rate”, because lenders set their own and no verified figure is available to us — the rate your lender quotes is the one that matters.
Read the detail in Flat rate vs reducing balance: how loan interest works in Tanzania, or browse all loans and finance calculators.
Frequently asked questions
What is the difference between APR and interest rate?
APR includes the interest rate plus most loan fees, giving a truer picture of the loan's annual cost.
How do I lower my monthly payment?
Extend the loan term, borrow less, or find a lower interest rate. Note that a longer term usually means more total interest.
Does this calculator include fees?
No. It covers principal and interest only; origination and other fees are excluded.
Does a longer term always mean paying more interest?
Yes, when the amount and the rate stay the same. Spreading the same balance over more months keeps it outstanding for longer, so more interest accrues even though the monthly payment falls.
Results are estimates provided for information only and do not constitute financial, legal or tax advice. Consult a qualified professional before making financial decisions.
Delta Tech Solutions prepared this page. No external tax, accounting or legal professional reviewed it — the figures were checked against the sources listed above, and you should confirm anything you rely on with the authority that sets it.
Maintained by David M at Delta Tech Solutions · Figures last checked 10 October 2026 · Next check due 10 April 2027
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