Budgeting & Debt
Leftover and share spent
What remains each month and how much of income the bills consume.
The Formula
Leftover = Income - Total; Share = Total / Income
What remains each month and how much of income the bills consume.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| I | Income | currency | Monthly take-home pay. |
| T | Total cost | currency | Sum of the monthly bills. |
What Each Symbol Means
Icurrency
Income
Monthly take-home pay.
Tcurrency
Total cost
Sum of the monthly bills.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate cost of living page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Cost Of Living, filed under Finance. Every number the guide produces comes from substituting into this one line.