If after a calculated, the net is negative, then you are not able to invest.
Forget about temporary investments time and try to turn the value to positive.
Conversely, if the net value is positive, decide whether it is sufficient to meet all your future requirements. Maybe the number should be increased so that more can be invested.
How to increase the net value of money?
One way is to reduce spending. Any excess cash of expenditure can be the list of assets to increase value net.
This is important because the money we spend will left us forever. So, save some to use in future where you might need it someday.