Allowance to Savings Calculator
Saving even a small share of a weekly allowance can build a surprising balance over a few years, and adding interest accelerates it. This calculator takes a weekly allowance, the share saved, an annual interest rate, and the number of years, then shows total deposits, interest earned, and the final balance. Every input is yours to set because allowance and savings habits are personal, not set by any official rate.
Allowance savings formula
Weekly saving = weekly allowance * (share / 100)
Monthly deposit = weekly saving * (52 / 12)
Monthly rate = (annual rate / 100) / 12
Each month: balance = balance * (1 + monthly rate) + monthly deposit
Total deposited = monthly deposit * 12 * years
Interest earned = final balance - total deposited
Deposits are grouped monthly using 52 divided by 12 weeks per month so the annual total stays exact. Interest compounds monthly. Setting the rate to zero gives the plain sum of deposits.
Building a savings habit
- Decide the savings share before spending so saving comes first, not last.
- Use a real account so the child sees the balance grow and interest appear.
- Set a goal and watch the final balance figure approach it as years increase.
- Review the interest rate against the account's current published rate.
Allowance savings: frequently asked questions
How does saving part of an allowance add up?
Setting aside a fixed share of each allowance turns small weekly amounts into a meaningful balance over time. This calculator multiplies the weekly allowance by the savings rate, totals the deposits over the period, and adds compound interest if you enter a rate.
How is the interest compounded?
Deposits are made weekly and interest is compounded monthly using the annual rate divided by twelve. Each month the running balance earns interest, then that month's four-and-a-third weeks of deposits are added. This mirrors how a basic savings account credits interest monthly.
What savings rate should a child use?
There is no official figure. A common teaching split is to save part, spend part, and give part. Because no government source sets this, the savings share is a user-editable input so you can match your own household plan.
Does the interest rate need to be exact?
No. Account rates change over time, so the rate here is a user input. Enter zero to see the plain sum of deposits with no growth, or enter your account's current annual percentage yield for an estimate of growth.
Notes and sources
- Allowance and savings-share amounts are not set by any government source; all figures here are user-editable inputs (CalculatorHub Tenet 3).
- Federal financial literacy guidance: MyMoney.gov (U.S. Financial Literacy and Education Commission).
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.