Savings Goal Calculator

How to Hit a Savings Goal

Most savings advice starts with "save more" — but the more useful question is "how much, exactly?" This calculator works backwards from your goal. You set the target and the deadline; it tells you the monthly amount that gets you there, with compound growth covering part of the distance. Seeing a concrete number ("R2,643 a month") turns a vague intention into a plan you can actually budget for.

The Formula (in Plain Terms)

It's the compound interest formula, rearranged to solve for the monthly contribution:

PMT = ( Target − Start × (1+i)ⁿ ) ÷ [ ((1+i)ⁿ − 1) ÷ i ]

First it grows your starting amount to what it'll be worth at the end. Whatever gap remains between that and your target is filled by monthly contributions — and because those contributions also earn growth along the way, you need to save less than the raw gap divided by the number of months.

A Worked Example

Suppose you want R1,000,000 in 15 years, starting from zero, earning 9% a year. You'd need to save about R2,643 a month. Over 15 years that's roughly R476,000 of your own money — meaning compound growth contributes the other R524,000, more than half the goal. Stretch the timeline to 20 years and the monthly figure drops well below R1,500, because growth has longer to do the heavy lifting. Time is the cheapest ingredient in any savings goal.

Keep It Tax-Free Where You Can

If your required monthly saving is R3,000 or less, the entire goal can sit inside a South African tax-free savings account (TFSA) — R36,000 per year, R500,000 lifetime, with no tax on growth. For larger goals, fill the TFSA first and hold the rest in a taxable account. Over a 15-year horizon, sheltering the growth from tax can be worth tens of thousands of rand on its own.

Related tools: the compound interest calculator works the other way — set a monthly amount and see what it grows to — and all savings tools are here.