Home Deposit Savings Planner
How long until you reach your 5%, 10% or 20% deposit?
About This Calculator
Enter your property target, take-home income, and monthly expenses — and see exactly how many months until you can afford a 5%, 10%, or 20% deposit.
Enter your actual spending below. The calculator instantly shows your monthly cost, annual cost, and 10-year total adjusted for 3% annual inflation. All calculations happen in your browser — nothing is stored or sent anywhere.
Frequently Asked Questions
How much deposit do I need to buy a house?
Most lenders require a minimum 5–10% deposit, but 20% is the target to avoid Lenders Mortgage Insurance (LMI) in Australia or Private Mortgage Insurance (PMI) in the US. On a $600,000 property, that's $30,000 (5%), $60,000 (10%), or $120,000 (20%).
How does the calculator work out how long I need to save?
It takes 80% of your monthly surplus (income minus expenses) as your savings rate, then divides the deposit target by your monthly savings. The 80% buffer accounts for irregular expenses and emergencies.
Why does the calculator use 80% of my surplus?
Most financial planners recommend not committing 100% of your surplus to a single goal. The 20% buffer covers irregular bills, medical expenses, car repairs, and other surprises that would otherwise derail your savings.
How can I save for a deposit faster?
The two levers are increasing income and reducing expenses. Every $100/month extra in savings cuts approximately 2–4 months off a 20% deposit timeline on a $500,000–$700,000 property.
Should I save a 5% or 20% deposit?
A 5% deposit gets you into the market faster but adds LMI/PMI costs (typically 1–3% of the loan) and higher ongoing repayments. A 20% deposit costs more up-front but saves tens of thousands over the life of the loan. The right answer depends on your market, timeline, and risk tolerance.
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Disclaimer: All calculators on CostXray are for informational and educational purposes only. Nothing on this site constitutes financial, legal, or investment advice. Default values are based on US averages. Always consult a qualified financial advisor before making financial decisions.