How to use the savings goal step up calculator
- Enter the savings goal and, if you have started, the amount already saved.
- Type the first monthly deposit and the increase each month. Use 0 for the increase to see a level deposit.
- Optionally add a yearly interest rate and the largest deposit you can make, which stops the deposit from rising past that amount.
- Read the number of months, the total deposited and the year by year table, and compare with the level deposit that reaches the same goal in the same time.
Formula
Deposit in month n = first deposit + (n - 1) x increase, capped at the largest deposit if you set one
Balance after month n = balance before x (1 + yearly rate / 12) + deposit in month n
The goal is reached in the first month the balance is at least the goal
Level deposit = (goal - saved x f) x i / (f - 1), where i = yearly rate / 12 and f = (1 + i)^months
Without interest the level deposit is simply (goal - already saved) / months. Deposits land at the end of each month, after that month's interest.
Starting at $100 and adding $10 a month
With a $10,000 goal, nothing saved yet, a first deposit of $100 and a $10 increase each month, the goal is reached in month 37. The deposits run from $100 up to $460, total $10,360, and the balance at that point is $10,360. Month 36 would have reached only $9,900.
A level deposit of $270.27 a month would reach the same $10,000 in the same 37 months. The step up plan starts much lower and ends much higher, which suits someone whose income is expected to grow. As a simpler check, deposits of $100 rising $10 over 12 months total $1,860.
When a rising deposit makes sense
A fixed deposit asks the most of you at the start, when money may be tightest. A rising deposit begins with an amount you can keep up and grows as raises, bonuses or paid-off bills free up cash. The tool shows how much sooner the goal arrives compared with staying at the first deposit.
If you can only raise the deposit so far, enter the largest deposit you can make. The plan then climbs to that amount and stays there, and the result shows how much longer it takes.
Reading the results
The year by year table splits deposits and interest so you can see how much of the balance comes from your own money. With a 0% rate, interest is zero and every dollar is a deposit.
For a single fixed deposit use the savings calculator, and for several goals with different deadlines use the savings goal calculator. The compound interest calculator shows growth on a lump sum.
Assumptions and limits
- Deposits are made at the end of each month and increase by exactly the amount you enter.
- Interest is the yearly rate divided by 12 and added to the balance before each month's deposit.
- The rate stays the same every month, and no taxes, fees or missed deposits are modeled.
- If the goal cannot be reached within 100 years, the tool asks you to change the numbers instead of showing a result.
Frequently asked questions
How long will it take to save if I increase my deposit every month?
Enter the goal, the first deposit and the monthly increase. The tool adds deposits month by month until the balance reaches the goal and reports the number of months.
What does the level deposit comparison show?
It is the single monthly amount that would reach the same goal in the same number of months at the same rate. It helps you see how the rising plan compares with saving the same amount every month.
Can I stop the deposit from growing at some point?
Yes. Enter the largest deposit you can make. The deposit rises each month until it reaches that amount and then stays there.
Is interest required?
No. Leave the rate blank for 0% and the result uses deposits only. If you add a rate it is applied monthly at one twelfth of the yearly figure.