Tool
Lifestyle Creep Calculator
See how much of a raise your new monthly costs already take, and what the rest could grow to if you keep it.
How to use it
The Lifestyle Creep Calculator shows how much of a raise your new monthly costs have already claimed. It helps anyone who just got more pay and wants to keep some of it. Start with Monthly take-home increase, in dollars. This is the raise after tax and deductions, per month, as it shows on your first new pay stub. Do not use the figure quoted before tax. Then list your New monthly costs, one per row, with a name and Dollars a month. The blank form has 3 rows. Add a cost gives you more, up to 8, and Remove takes one out. A row with a name but no amount stays out of the sums. A cost paid once a year goes in as the yearly amount divided by 12.
Next, set Years to project, from 1 to 40 (it starts at 10). Then set Yearly return on what you keep, in percent, from 0 to 15 (it starts at 4). The result updates as you type. It pairs with our playbook on lifestyle creep after a raise.
The result
The form needs JavaScript to recalculate. Without it, the result below stays on the example.
$205 of a $350 raise is already spoken for: 59 percent.
That leaves $145 a month to keep, $1,740 a year.
Saved every month for 10 years at 4 percent a year, the $145 grows to about $21,351, of which $17,400 is what you put in.
The new costs, saved instead, would have grown to about $30,186.
The 4 percent return is an assumption, not advice. No tax or inflation is counted, and every cost is held flat.
Example: a made-up raise and three made-up costs, in round figures.
Each cost
Largest first. The last column is what each would grow to in 10 years if saved instead at 4 percent.
| Cost | A month | A year | In 10 years |
|---|---|---|---|
| more meals out | $120 | $1,440 | $17,670 |
| gym with a pool | $60 | $720 | $8,835 |
| streaming bundle | $25 | $300 | $3,681 |
| All new costs | $205 | $2,460 | $30,186 |
The split, decided before the raise lands
These are illustrative figures: the split from our lifestyle creep playbook, half of the raise to saving, a quarter to a goal or a debt and a quarter to spend.
The new costs, $205 a month, already take more than the $87 spend share.
How the numbers work
Each figure follows a fixed rule. The example's $350 raise shows them at work:
- Creep. Your new monthly costs added up. The example has a gym with a pool at $60, a streaming bundle at $25 and $120 more in meals out, which make $205 a month. A year is the monthly figure times 12, so that is $2,460.
- Creep share. The creep divided by the monthly take-home increase, shown as a whole percent. Here, $205 of a $350 raise is already spoken for: 59 percent.
- Kept. The monthly take-home increase minus the creep: $145 a month, or $1,740 a year. When the costs add up to more than the raise, the result says by how much a month and shows no growth figure here.
- Kept and saved. A monthly amount saved at the end of each month for the years you chose, growing each month at the yearly return divided by 12. The return is an assumption, not advice. At 4 percent, $145 a month grows to about $21,351 in 10 years, and $17,400 of that is the amounts put in. At 0 percent it is just the monthly amount times the months.
- What the creep would have grown to. The same growth on the creep, as if those costs had been saved: about $30,186, with $24,600 put in. A table of each cost lists the rows largest first, with monthly, yearly and grown amounts.
- The split. The playbook's split, labeled illustrative figures: half to saving, a quarter to a goal or a debt, a quarter to spend. A $350 raise splits into $175, $88 and $87, and the result compares the creep with the $87.
What this does and does not tell you
It tells you, in one number, how much of your raise is gone before you ever feel richer. The creep share is the figure to watch. In the example, the new costs already take more than the whole $87 spend share. That means the creep is eating into money the playbook would send to saving or a goal. The table of each cost shows where to look first. More meals out, at $120 a month, would have grown to about $17,670 over 10 years.
It cannot see everything. There is no tax: you enter take-home pay, and the growth figures are before any tax on what the savings earn. There is no inflation, so every figure is in plain dollars. The return is held steady every month, while real returns vary from year to year and can be negative. Each cost stays flat, so price rises on a subscription or a membership are not counted. The split is an illustration, not a rule. And the tool does not know which costs were worth it. A cost you chose on purpose, at a calm moment, is a choice, not creep. The tool only shows its size. Our entry on the hedonic treadmill explains why the lift from an upgrade fades while its bill does not.
It is also only for costs that repeat. A one-time purchase does not belong here. The Chain Cost Calculator adds those up, including the purchases one buy pulls in after it.
Questions readers ask
How do I enter a cost I pay once a year?
Divide the yearly amount by 12 and enter that in Dollars a month. A membership billed $120 once a year goes in as $10. The playbook also suggests pricing any cost that repeats over a year and over five years before you sign up, and the table in the result shows each cost's yearly amount next to its monthly one.
What should I do if the result says my new costs exceed the raise?
It means the costs you listed add up to more than the monthly take-home increase, so the raise is already gone and then some. The result shows how much over you are each month and gives no growth figure for a kept amount, because there is none. Start with the largest row in the table, and cancel or downgrade at least one cost that crept in rather than one you chose.
Why is the growth figure bigger than what I put in?
Because it assumes each month's amount is saved at the end of the month and earns the yearly return you entered, divided by 12, every month for the years you chose. The result shows how much of the total is your own amounts put in. In the example, $145 a month over 10 years is $17,400 put in and about $21,351 at 4 percent. Enter 0 for the return to see the plain sums. The return is an assumption, not advice.
Do you keep what I enter?
The form works in your browser and sends nothing to us; the result is in the page address so you can share it. Reloading the page or opening a shared link sends that address to our host like any other page request. Nothing goes into your browser storage.