Before thinking about investing you need one number: how much is left over each month. If that number is negative, which investment is halal has no practical bearing — you have nothing to invest.
Most people do not know this number. Because they do not know it, they cannot improve it.
How to work out the gap
- Take your monthly take-home income — after tax, what actually reaches you.
- Subtract the average monthly figure from the three months you collected in the last lesson.
- What remains is your monthly gap.
The breaking-even calculator on this site does the same arithmetic for you and names your largest expense. The figures you type never leave your browser.
If the gap is positive
Good. The question is now where that money goes. Surplus left sitting in a current account tends to be spent without anyone deciding to spend it. The next lessons give it somewhere to go.
If the gap is negative
There are two sides: raise income or cut spending. In the short term the spending side moves faster, because it is entirely under your control. The income side is more powerful but slower.
Leaving a negative gap on the assumption that next month will be better is the most expensive option available: while the gap stays negative the shortfall is filled with debt, and the debt then adds its own repayment to the spending list, which makes the gap more negative still.
A deficit is not a state. It is a loop that grows itself.
One caution
This number is not "good" or "bad" on its own. The same gap means completely different things for a salaried employee and for someone whose income arrives unevenly. The number measures your situation, not you.