Deposit Interest Calculator

What could a lump-sum deposit
be worth at maturity?

Check the interest a lump-sum deposit could earn and the payout after tax. Adjust the amount, rate and term to explore the result. The estimate assumes you keep the deposit until maturity.

DEPOSIT MATURITY SCENARIOS

Compare after-tax interest and maturity value
by deposit, rate, and term.

These examples assume 3.5% simple interest and no tax deduction.

Principal, interest, tax, and maturity value are calculated estimates. Actual results can differ because of day-count conventions, rounding, and product terms.

By deposit amount

1 year · 3.5% annual rate · simple interest · no tax deducted

Principal: $10,000
Pre-tax interest: $350
Estimated tax: $0
After-tax interest: $350
Maturity value: $10,350

Principal: $30,000
Pre-tax interest: $1,050
Estimated tax: $0
After-tax interest: $1,050
Maturity value: $31,050

Principal: $50,000
Pre-tax interest: $1,750
Estimated tax: $0
After-tax interest: $1,750
Maturity value: $51,750

Principal: $100,000
Pre-tax interest: $3,500
Estimated tax: $0
After-tax interest: $3,500
Maturity value: $103,500

By annual rate

Deposit $10,000 · 1 year · simple interest · no tax deducted

Annual rate: 3%
Pre-tax interest: $300
Estimated tax: $0
After-tax interest: $300
Maturity value: $10,300

Annual rate: 4%
Pre-tax interest: $400
Estimated tax: $0
After-tax interest: $400
Maturity value: $10,400

Annual rate: 5%
Pre-tax interest: $500
Estimated tax: $0
After-tax interest: $500
Maturity value: $10,500

By deposit term

Deposit $10,000 · 3.5% annual rate · simple interest · no tax deducted

Term: 1 years
Pre-tax interest: $350
Estimated tax: $0
After-tax interest: $350
Maturity value: $10,350

Term: 2 years
Pre-tax interest: $700
Estimated tax: $0
After-tax interest: $700
Maturity value: $10,700

Term: 3 years
Pre-tax interest: $1,050
Estimated tax: $0
After-tax interest: $1,050
Maturity value: $11,050

How it works

Separate principal growth,
interest, and tax.

The interest calculated from the stated rate may differ from what you receive. Subtract interest tax from pre-tax interest, then add your principal to estimate the maturity value. Change the deposit amount, term, and rate to compare deposit scenarios.

Pre-tax interest − interest tax = after-tax interest
Principal + after-tax interest = maturity value

How is a lump-sum deposit different from recurring savings?

A lump-sum deposit places all principal at the start, so the full amount earns interest for the entire term. Recurring savings adds money over time, giving each deposit a different interest period.

Simple interest and monthly compounding

Simple interest applies only to principal. Monthly compounding includes previously earned interest in later calculations. Select the method stated in the product terms.

Tax and deposit protection

The default English estimate does not deduct tax. Enter a custom rate when needed. Deposit insurance coverage depends on the institution, product, and jurisdiction, so verify the applicable protection before opening an account.

Depositing $10,000 for one year at 3.5%

This example uses simple interest and does not deduct tax.

Principal: $10,000
Estimated interest: $350
Estimated maturity value: $10,350

Actual results may differ because of day-count conventions, compounding frequency, rounding, taxes, and product terms.

Frequently asked questions

Is the annual rate the same as my after-tax return?

No. The stated annual rate is before tax. The term, compounding method, and tax rate change the actual return on principal.

Do all term deposits compound monthly?

No. Many use simple interest or another compounding frequency. Choose monthly compounding only when the product terms say so.

What happens if I withdraw early?

An early-withdrawal rate or penalty may apply. This calculator models a deposit held through maturity.

What could a lump-sum depositbe worth at maturity?

Assumptions

Compare after-tax interest and maturity valueby deposit, rate, and term.