There is no single correct monthly savings figure; it depends on your goal, your timeline and the room in your budget. What you can do is turn a vague intention into a concrete number using a simple formula, then check whether that number fits. This guide explains the maths and the common rules of thumb so you can set your own target.
The basic idea: work backwards from a goal
For a goal with no interest, the required monthly amount is simply target ÷ months. If you want $6,000 in two years, that is 6,000 ÷ 24 = $250 a month. If you want $3,000 in six months, it is 3,000 ÷ 6 = $500 a month. The sooner the deadline, the larger each payment has to be.
When interest is involved
If the money earns interest, each contribution grows, so you need to put in less than the flat division suggests. The relationship is the compound savings formula, where regular deposits plus growth reach the target. A savings projection can show the gap, but the result depends on an assumed rate, which may not hold. Treat any projected figure as an illustration, not a forecast.
Common rules of thumb
| Rule | What it suggests | Notes |
|---|---|---|
| 50/30/20 | 20% of take-home pay to savings | A rough split of needs, wants and saving; not suited to every income. |
| Pay yourself first | Save as soon as income arrives | Removes the temptation to spend what is left. |
| Emergency fund | 3–6 months of essential expenses | A buffer size, not a monthly amount; common guidance varies. |
| Save a raise | Bank part of any increase | Keeps your spending from rising with income. |
These are starting points, not rules you must follow. A person with high fixed costs and a modest income may not be able to set aside 20%, and that is a budgeting reality rather than a failure.
An example with numbers
Suppose your essential monthly outgoings are $2,200 and you want a six-month cushion. The target is 2,200 × 6 = $13,200. Over 18 months, that is roughly 13,200 ÷ 18 ≈ $733 a month. Over 36 months, it drops to about $367 a month. Same goal, different deadline, very different pressure on your budget.
Deciding what you can actually afford
- Note your take-home income for a month.
- Subtract essential costs: housing, food, transport, bills, minimum debt payments.
- Look at what remains and choose a share you can sustain every month, not just once.
- Automate the transfer so it happens without a decision each time.
- Review the amount when your income or costs change.
Keep it realistic
A number you can maintain beats a heroic figure you abandon after two months. Start with an amount that leaves room for normal life, and increase it gradually. This article is general information rather than personalised financial advice; your circumstances are unique, and a qualified adviser can help with decisions specific to you.
To see how a starting balance plus monthly contributions might grow over time under different assumptions, try our savings calculator. If you are weighing a loan instead, the total cost of a loan guide shows the other side of the balance sheet.