# Interest Rate Calculator

URL: https://speedycalculator.com/calculators/finance/interest-rate/
Last updated: 2026-10-25

> The interest rate calculator finds the interest rate on a loan from the amount, term and payment – or the rate a deposit earns from its initial and current balance – and gives the effective annual rate and the APR including fees.

## Inputs

- Calculate for
- Loan amount
- Periodic payment
- Term (years, months)
- Payment frequency
- Upfront fees
- Initial deposit
- Current balance

## Results

- Periodic rate
- Annual interest rate (nominal)
- Effective annual rate
- APR (including fees)
- Total interest

## Formula

```
Loan: solve P = PMT × [1 − (1 + i)^−n] ÷ i for i; nominal rate = i × payments per year
Deposit: rate = (balance ÷ deposit)^(1 ÷ years) − 1
APR: same calculation using loan amount minus fees
```

## Explanation

If a lender only tells you the payment, this works out the rate you are really paying. Including upfront fees gives the APR, which is the fair way to compare loan offers.

### How to use the Interest Rate Calculator

- **Calculate for**
- **Loan amount**
- **Periodic payment**
- **Term**
- **Payment frequency**
- **Upfront fees**
- **Initial deposit**
- **Current balance**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Choose loan or deposit and enter the figures.

### Tips

- Use the nominal annual rate and pick the compounding frequency your bank or broker states.
- Small differences in return or fees compound into large differences over decades.
- Run the calculation with a cautious, a central and an optimistic return to see the range of outcomes.
- Past returns do not guarantee future returns – nothing here is investment advice.

### Common mistakes to avoid

- Comparing an APR with an APY or effective rate.
- Ignoring inflation, taxes and fees when judging a real return.
- Entering a percentage as a decimal (5 instead of 0.05 is correct here).

### Inputs explained

FieldWhat to enterCalculate forChoose one: Loan, DepositLoan amountAmount in your currencyPeriodic paymentAmount in your currencyTermUnits: years, monthsPayment frequencyChoose one: Monthly, Semi-monthly, Bi-weekly, Weekly …Upfront feesAmount in your currencyInitial depositAmount in your currencyCurrent balanceAmount in your currency

### What each result means

- **Annual interest rate (nominal)** = [Periodic rate]×[Payment frequency]
- **Effective annual rate** = ((1 + [Periodic rate]÷100)^[Payment frequency] - 1)×100

### Example values

How the main result changes when **Loan amount** changes and everything else stays at the example values above:

Loan amountAnnual interest rate (nominal) (%)10,00041.86815,00020.3120,0007.4225,000-1.59530,000-8.45540,000-18.534

## Worked example

Inputs — Calculate for: Loan; Loan amount: $20,000; Periodic payment: $400; Term: 5 years; Payment frequency: Monthly; Upfront fees: $300; Initial deposit: $10,000; Current balance: $11,500.

Results — Periodic rate = 0.6183 %; **Annual interest rate (nominal) = 7.42 %**; Effective annual rate = 7.678 %; APR (including fees) = 8.059 %; Total interest = $4,000.00.

## FAQ

**How do I find the interest rate on a loan?**
Solve the loan payment formula for the rate – this calculator does it numerically.

**What is the difference between the interest rate and APR?**
APR includes fees, so it is higher when fees are charged.

**Why does the effective rate exceed the nominal rate?**
Because interest compounds within the year.

**What formula does the Interest Rate Calculator use?**
Loan: solve P = PMT × [1 − (1 + i)^−n] ÷ i for i; nominal rate = i × payments per year.


## Sources

- [Consumer Financial Protection Bureau](https://www.consumerfinance.gov/)