How to Calculate Salary Inflation — Step by Step

The formula, in one paragraph

Four steps. First, the factor: one plus the inflation rate, raised to the years. Second, the salary you will need: your salary times the factor. Third, the real value: your salary divided by the factor. Fourth, the loss: your salary minus the real value. The same factor answers the raise question: your salary times one plus the raise, raised to the years, is the nominal pay, and dividing it by the factor gives its real value.

Step 1: Work out the factor

Take one plus the inflation rate and raise it to the years. At the example — 3% inflation over 10 years — the factor is 1.03 to the power of 10, which is 1.3439. That number says prices rise 34.39% over the decade, so every dollar buys about a quarter less.

Step 2: Work out the salary you will need

Multiply your salary by the factor. At the example, $75,000 times 1.3439 is $100,793.73. That is the pay that buys in 10 years what $75,000 buys today — not a raise, just keeping up. Per month that is $8,399.48 against $6,250.00 today: a gain of $2,149.48 a month is needed.

Step 3: Work out what today’s salary will be worth

Divide your salary by the factor. At the example, $75,000 divided by 1.3439 is $55,807.04. If your pay stays at $75,000, it will be worth $55,807.04 in 10 years. The loss is $75,000 minus $55,807.04, which is $19,192.96 — a quarter of the salary, gone in real terms. Per month the real value is $4,650.59.

Step 4: Work out what a raise does

Run the same compounding on your raise. A 2% annual raise turns $75,000 into $75,000 times 1.02 to the power of 10, which is $91,424.58 after 10 years. Its real value is $91,424.58 divided by 1.3439, which is $68,028.47. The shortfall is $100,793.73 minus $91,424.58: $9,369.15 a year. A 2% raise sounds close to 3% inflation, but the raise compounds on a smaller base than the price level, so it still leaves you $9,369.15 a year short. A 4% raise does get ahead: $111,018.32 nominal, $82,608.06 real, $7,608.06 ahead in real terms.

How fast your pay halves

The rule is the natural log of 2 divided by the natural log of one plus the inflation rate. At 3% that is 23.45 years: $75,000 buys what $37,500 buys today. The rule of 72 gives 24 years, close to the exact 23.45. At 5% it halves in 14.21 years, and at 2% in 35.00 years. Smaller questions work the same way: $75,000 is worth $50,000 after 13.72 years at 3%, and worth $60,000 after 7.55 years.

How to find your own inflation rate

The Consumer Price Index, or CPI, tracks an average household, not yours. Start with the CPI-U, published monthly by the Bureau of Labor Statistics: its long-run average is about 3% a year, but it peaked at 9.1% in 2022. Then check your own costs: add up what rent, food, transport and childcare cost a year ago and now, and divide the difference by last year’s total. If your costs rose 5% while the CPI rose 3%, use 5%.

What to do about it

Negotiate a raise at or above inflation, with the number in hand. Walk in with the future salary figured out — $100,793.73 in 10 years at the example — and ask for a raise that matches inflation every year. A raise below inflation is a pay cut with a nicer name: at 2% against 3% inflation you lose $9,369.15 a year of ground by year ten. If the employer cannot match inflation in cash, ask for the same value another way: a bonus, more paid time off, a remote-work day, or training that raises your market rate. And if the pay will not move at all, look elsewhere: staying put at $75,000 for 10 years costs $19,192.96 of buying power.

What NOT to do

A 2% raise against 3% inflation is a 1% pay cut, not a raise. Do not use the average rate when your own costs run hotter. Do not forget that the loss compounds: $19,192.96 over 10 years becomes $33,474.32 over 20 years at the same 3%. Check every year, with that year’s inflation, so a small shortfall never becomes a large one.

That box is the whole formula.