Monthly savings required to reach a target home deposit

The Deposit Math

A 400,000 home at 10% deposit requires 40,000 saved. With 5,000 already saved at 4% return, growing to roughly 6,700 in 5 years, the gap is 33,300. Saving that over 60 months at 4% return requires about 500/month. Shorter timelines or bigger deposits raise the required monthly amount steeply.

Deposit Percent Choices

5% deposit (first-time buyer products): often available via shared-ownership and similar low-deposit schemes. 10% deposit: broadest lender availability. 15-20% deposit: access to lower rates and larger loan-to-value. Each tier changes both the saving requirement and subsequent mortgage rate.

Factors Outside the Calculator

Mortgage fees (1,000-2,500), legal fees (1,500-3,000), surveys (400-1,500), property transfer tax (variable), and moving costs add 5,000-15,000 of additional cash needed. A prudent target adds 10-15% to the deposit figure to cover these. The calculator handles deposit only; budget separately for the rest.

Run it with sensible defaults

Using target house price of 400,000, deposit percent of 10, current savings toward deposit of 5,000, years until purchase of 5, the calculation works out to approx 504/mo. Nudge the inputs toward your own situation and the output recalculates instantly. The defaults are meant as a starting point, not a recommendation.

The levers in this calculation

The inputs — Target House Price, Deposit Percent, Current Savings Toward Deposit, Years Until Purchase, and Savings Account Rate — do not pull with equal force. Not every input has equal weight. Flip one at a time toward extreme values to feel which ones move the needle most for your situation.

How the math works

Deposit target equals house price times deposit percent. Future value of current savings at purchase date calculated. Gap divided by annuity factor yields monthly savings required. Results are estimates for illustration purposes only. The working is transparent — you can verify every step yourself in the formula section below. No black box, no opaque "proprietary model".

Turning the result into a plan

A projection is just a starting point. The real work is setting the monthly amount aside automatically so the saving happens before you can spend it. Most people who hit savings goals set up a standing order on payday; most who miss them rely on willpower at month-end.

What this doesn't capture

The calculation assumes a steady savings rate and a stable interest rate. Real saving journeys include emergencies, windfalls, and rate changes — especially in easy-access products. The figure is a direction of travel, not a guarantee.