🏦 Savings Calculator
See what a savings plan grows to, how much of it is interest rather than your own money, and how long a goal takes to reach at your current deposit.
Building a savings balance, and how long a goal actually takes
A savings plan has three moving parts: what you start with, what you add, and what the bank pays. Over short horizons the deposits dominate and the interest is almost irrelevant. Over long ones that reverses. Knowing which regime you are in tells you whether to spend your effort chasing a better rate or simply saving more.
balance = P(1 + r/12)12t + PMT × [ ((1 + r/12)12t − 1) / (r/12) ]
When the rate starts to matter
| Years | At 1% | At 4.5% | Difference |
|---|---|---|---|
| 1 | $3,617 | $3,677 | $60 |
| 3 | $10,966 | $11,560 | $594 |
| 5 | $18,459 | $20,181 | $1,722 |
| 10 | $37,844 | $45,409 | $7,565 |
| 20 | $79,629 | $116,222 | $36,593 |
Over a year, the gap between a terrible rate and a good one is $60 on $3,600 saved. Over twenty years it is $36,593. For an emergency fund you are building this year, the rate barely matters and accessibility does. For a deposit you are building over a decade, it matters a great deal.
The emergency fund comes first
Before any goal-based saving, most guidance puts three to six months of essential expenses in an instantly accessible account. Not three to six months of income: of the spending you could not avoid, which is usually 60% to 75% of income. For someone spending $2,800 a month on essentials, that is $8,400 to $16,800.
An emergency fund is insurance, not an investment. Keep it somewhere boring and instantly accessible. Earning 1% less on $12,000 costs $120 a year; having it locked up when the boiler fails costs far more.
Where to keep it
| Account | Access | Suits |
|---|---|---|
| Instant-access savings | Immediate | Emergency fund, short-term goals |
| Notice account | 30–120 days | Known spending more than 6 months away |
| Fixed-term deposit or CD | Locked for the term | Money you are certain you will not need |
| Money market fund | 1–2 days typically | Larger balances, slightly higher yield |
| Investment account | Variable, can fall | Horizons beyond about five years |
The rough dividing line is five years. Below that, market volatility is a real risk to money you have a date for. Above it, inflation is the larger risk and cash is the thing losing value.
Pay yourself first
A standing order on payday, before anything else leaves the account, consistently outperforms the intention to save what is left at the end of the month. It removes the monthly decision, which is where the plan usually fails. Increasing the amount with each pay rise, rather than absorbing the rise into spending, is the single most effective habit in this whole area.
Inflation, again
A savings account paying 4.5% while inflation runs at 3% is earning a real return of (1.045 / 1.03) − 1 = 1.46%. That is still positive, which is better than most cash has managed historically, but a balance that doubles in nominal terms over sixteen years will not double in purchasing power. For goals more than a decade out, run the figure through the inflation calculator as well.
A worked example
A $25,000 deposit goal, starting from $2,000, saving $300 a month at 4.5%. The goal is reached in 5 years and 7 months, by which point you will have deposited $22,100 and earned $2,900 in interest. Raising the deposit to $400 a month pulls it forward to 4 years and 5 months, and saving the same $300 at 1% instead of 4.5% pushes it out to 6 years and 2 months.
Frequently Asked Questions (FAQs)
How much should I have in an emergency fund?
Three to six months of essential expenses, not of income. Lean towards six if your income is variable, you are self-employed, or you are the sole earner. One month is a reasonable first target if starting from nothing, because most emergencies are smaller than people fear.
Is it better to save or pay off debt first?
Build a small buffer of around one month's expenses, then clear anything above about 8% interest, then return to saving. Paying off a 22% credit card is a guaranteed 22% return, which no savings account will match. Low-rate debt such as a mortgage is a closer call.
What is APY and why does it differ from the advertised rate?
APY is the annual yield after compounding, which is what you actually earn. A 4.4% nominal rate compounded monthly gives a 4.49% APY. Savings accounts are normally advertised by APY, so comparing APY to APY is the only fair comparison.
Should I save monthly or in a lump sum when I can?
Monthly, automated. Each deposit starts earning sooner and the automation removes the decision. Saving ad hoc when money is left over reliably produces less, because there is usually less left over than expected.
Does this calculator account for tax on interest?
No. In most countries savings interest is taxable, though many have an allowance or a tax-free wrapper. Reduce the rate you enter by your marginal tax rate to get an after-tax figure, or use a tax-sheltered account where available.
What if the interest rate changes?
Most instant-access rates are variable and will change, often downwards after an introductory period. Run the calculation at a conservative long-run rate rather than at a promotional one, and check what your account is paying once a year.