Drawdown · 4% rule · Early retirement

Compound Interest with Withdrawals

Q: How do I enter a withdrawal?

Under Regular contributions, choose Withdrawals, then enter the Withdrawal amount and how often it comes out — monthly, quarterly, or annually. For example, enter 3,333 with monthly selected to draw $3,333 a month from the balance.

Q: Can I mix deposits and withdrawals?

Yes — choose Both to run deposits and withdrawals side by side, each with its own amount, frequency, and yearly increase. Both run for the whole time horizon, so to model saving for 10 years and then drawing down for 20, run two scenarios: use the first one's final balance as the second one's initial amount.

Enter a negative monthly amount to drain the account on a schedule. The year-by-year table shows how long the balance lasts.

Load scenario4% rule, $1M Early retire · $800k Coast FI · $500k

Live·Updates on every change

Inputs

Currency

Initial amount

Annual interest rate

Time horizon

Years:

Months:

Compound frequency

Regular contributions: (optional)

Deposit amount: (optional)

Annual deposit increase? (optional)

Inflation & tax⌄

Annual inflation rate

Shown as a "real" value in today's money.

Tax on gains

Applied once at the end of the horizon.

Future value

—

After

—

Contributed

—

Principal + deposits

Interest earned

—

Effective APY

—

Growth over time

Principal, contributions, and interest — stacked year by year.

PrincipalContributionsInterest

Year-by-year breakdown

Opening balance, deposits, interest, closing balance.

Show table

Year	Opening	Net flows	Interest	Closing

How withdrawals work

Negative deposits = withdrawals.

Most compound interest calculators silently assume you're only adding money. This one lets you subtract it. Enter a negative number in the deposit field and every period the calculator pulls that amount out of the balance before compounding the rest. The future-value tile tells you the end balance; the year-by-year table tells you whether the plan ran out of money along the way.

Example · 4% rule

Start with $1,000,000. Withdraw $3,333/month ($40k/yr). Earn 6% nominal, 3% inflation.

Horizon30 years
Total withdrawn~$1.2M
Ending balance~$1.4M

Static-rate baseline — real markets vary year to year.

FAQ

Frequently asked

How do I enter a withdrawal?

Under Regular contributions, choose Withdrawals, then enter the Withdrawal amount and how often it comes out — monthly, quarterly, or annually. For example, enter 3,333 with monthly selected to draw $3,333 a month from the balance.

What's the 4% rule?

The Trinity-study rule of thumb: withdraw 4% of your starting balance in the first year, raise that amount with inflation each year after, and a diversified portfolio has a high chance of lasting 30+ years. On a $1M nest egg that's about $3,333/month. To model the inflation raise, set Annual withdrawal % increase to your inflation assumption.

Does the calculator account for sequence-of-returns risk?

No. It assumes a constant rate every year. For a volatile drawdown — where early bad years can sink a portfolio — use a Monte Carlo tool. This calculator is best for the deterministic baseline.

What happens if withdrawals exceed interest?

The balance shrinks. The year-by-year table shows the closing balance falling each year as withdrawals outpace the interest earned. If the balance drops below zero, treat that as the year the money runs out — the calculator keeps running the math, but the plan has already failed by then.

Can I mix deposits and withdrawals?

Yes — choose Both to run deposits and withdrawals side by side, each with its own amount, frequency, and yearly increase. Both run for the whole time horizon, so to model saving for 10 years and then drawing down for 20, run two scenarios: use the first one's final balance as the second one's initial amount.

Will the money last?

Change the rate, the withdrawal, or the horizon and watch the balance curve react.

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