- What is the future value formula?
- FV = PV × (1 + i)^n + PMT × ((1 + i)^n − 1) ÷ i. PV is your starting amount, PMT is the deposit each period, i is the rate per period (annual rate ÷ periods per year) and n is the number of periods (years × periods per year). With $10,000 to start, $200 a month, 6% a year and 10 years, i = 0.005 and n = 120, so FV = $50,969.84. If deposits land at the start of each period, multiply the deposit part by (1 + i). If the rate is 0, it's just PV + PMT × n.
- What's the difference between end of period and start of period deposits?
- End of period (an ordinary annuity) means each deposit arrives after the period's interest is paid, so the last deposit earns nothing. Start of period (an annuity due) means each deposit goes in first and earns a full period of interest. Start always ends a little higher: $1,000 a year at 5% for 10 years grows to $12,577.89 with end-of-year deposits and $13,206.79 with start-of-year deposits. Most savings plans that pull money on payday are closer to start of period; loan-style payments are end of period.
- How do I calculate future value in Excel or Google Sheets?
- Use =FV(rate, nper, pmt, pv, type). Rate is per period, nper is the number of periods, pmt is the deposit, pv is the starting amount, and type is 0 for end of period or 1 for start. Money you pay in is negative, which is why the answer comes back positive. For $10,000 plus $200 a month at 6% for 10 years, type =FV(6%/12, 120, -200, -10000, 0) and Sheets returns 50969.84. This calculator writes that formula for your numbers, so you don't have to remember the argument order or the sign rule.
- Does compounding frequency change the future value much?
- Less than most people expect, once you're past yearly. $10,000 at 6% for 10 years with no deposits grows to $17,908.48 compounded yearly, $18,140.18 quarterly, $18,193.97 monthly and $18,220.29 daily. Going from monthly to daily adds about $26 over ten years. The rate and the number of years matter far more. Here one Frequency setting drives both deposits and compounding, which matches how most savings accounts and spreadsheet FV problems work.
- How much of my future value is interest versus my own money?
- The breakdown under the result shows it. You started with is your starting amount, You deposited is the deposit times the number of periods, and Interest earned is whatever is left. In the default example, $10,000 plus $24,000 of deposits grows to $50,969.84, so interest added $16,969.84. Time changes the split fast: $500 a month at 7% becomes $260,463.33 after 20 years, of which $140,463.33 is interest, and $609,985.50 after 30 years, of which $429,985.50 is interest.
- Why would I use a negative interest rate?
- To see what your money is worth in today's dollars. If an account pays 1% and inflation runs 3%, your real return is about −2% a year. $10,000 at −2% for 10 years comes to $8,170.73, so the calculator shows Interest earned as −$1,829.27, meaning you lost that much buying power. Rates above −100% are allowed. At −100% or below the balance is wiped out, so the calculator asks for a higher rate.
- What if the years don't divide evenly into periods?
- The number of periods is rounded to the nearest whole period, because deposits and compounding happen in whole steps. 2.5 years quarterly is exactly 10 periods. 2.3 years quarterly is 9.2, which rounds to 9. The formula line shows the rounding, like n = round(2.3 × 4) = 9, and the by-year table adds a final row for the partial year so its balance matches the result.
- How is future value different from compound interest or a savings goal?
- They're three views of the same math. The Compound Interest Calculator focuses on a lump sum growing over time. This calculator adds regular deposits and deposit timing, and answers what you'll end up with. The Savings Goal Calculator runs it backwards: you give it the target, and it tells you the deposit you need. If you're comparing two past investments rather than projecting a future one, the CAGR Calculator gives the growth rate between a start and end value.
- Why does a very large result show up like $5.38e+30?
- Anything of $1,000,000,000,000,000 or more is written in scientific notation so it stays readable and doesn't run off the screen. $5.38e+30 means 5.38 with the decimal point moved 30 places right. You'll only see it with extreme inputs, like $1 billion plus $100,000 a day at 50% for 100 years. Real plans stay in plain dollars and cents.
