Calculators
Compound savings calculator
Saving for a home deposit, a renovation or a rainy-day fund? Work out the regular deposit that gets you to a target by a set date, or see what your current saving habit grows to with compound interest.
Deposit needed
$0
Total deposited
$0
Interest earned
$0
before any tax
In today's dollars
$0
This calculator gives estimates for general information only. It is not credit advice or an offer of credit, and it does not take into account your objectives, financial situation or needs. Results depend on the figures you enter and the assumptions shown below, which you can edit. Actual amounts will vary with lender fees, charges and credit criteria. Consider your circumstances and seek advice before acting. Talk to us and we'll search for options available to you across 60+ lenders.
The interest rate shown is an editable example only, not an offer, a current market rate or a suggestion about any product. Savings account rates are variable and change over time, so long-range projections are indicative only. Interest you earn is generally taxable income - talk to your accountant about your situation. Projections of two years or more are also shown in today's dollars, adjusted for assumed inflation.
Assumptions (you can change these)
Every figure this calculator relies on is editable: the target or regular deposit, starting balance, interest rate, deposit frequency and term in the form above, plus the inflation rate below. The conventions underneath describe how the maths works.
Compounding convention: interest is calculated and compounded once per deposit period (the annual rate divided by 52, 26 or 12), and each deposit is credited at the end of its period, after that period's interest. For monthly deposits this is exactly monthly compounding. For weekly and fortnightly deposits the compounding follows the deposit cycle; real savings accounts usually calculate interest daily and pay it monthly, which lands very close to this model (the difference is well under half a percent over typical terms).
The required deposit in target mode is solved with the standard annuity formula and the same convention, so depositing that exact amount each period lands on the target at the end of the term. The date shown is when the balance first crosses the target using the deposit rounded to the cent.
The interest rate is assumed to stay the same for the whole term. Savings rates are variable in practice, including bonus-rate conditions that can change the rate you actually receive month to month.
No account fees and no tax are modelled. Interest is generally assessable income at your marginal tax rate - your accountant can tell you what that means for your projection.
The today's-dollars figure discounts the end amount by the assumed inflation rate above (defaulted to 2.5%, the midpoint of the RBA's target band) so you can see what the projection would buy today. It appears for terms of two years or more.
Plain English
Saving for a home deposit
Most people use this calculator for one thing: the house deposit. Working backwards from a target is powerful - instead of "we save what's left over", you get a concrete number per week, and a date. Compound interest quietly does part of the work: the interest band in the chart above grows faster the longer you leave it.
Tips that make the number smaller
- Start earlier, even smaller. Time in the account matters more than the size of any single deposit.
- Match the deposit to payday. A transfer that happens automatically the day you're paid is the one that actually happens.
- Check the rate conditions. Many accounts pay a bonus rate only if you deposit monthly and make no withdrawals - missing a condition can cost most of a month's interest.
- First home buyer? Look at the FHSS. The First Home Super Saver scheme can let eligible buyers save part of a first-home deposit through voluntary super contributions with concessional tax treatment. That's general information, not advice - eligibility rules and caps apply, so check the ATO's guidance or ask us where to start.
How much deposit do you actually need?
It varies. A 20% deposit avoids Lenders Mortgage Insurance, but plenty of buyers purchase with less, and government schemes can lower the bar for eligible first home buyers. Deposit size also interacts with stamp duty and other buying costs, which are on top of the deposit itself.
When you're within reach of a deposit, talk to us. We'll look at your savings pattern the way a lender will (genuine savings matter), map the schemes you may be eligible for, and work out the price range your deposit realistically supports - across 60+ lenders, in plain English.
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