📊 Savings Withdrawal Calculator

$250,000 earning 4 percent APY with $1,500 withdrawn monthly lasts 20.1 years. The interest slows the drain: without any yield the same balance covers just 13.9 years. This calculator solves the exact month count, shows the total you will withdraw, and names the sustainable amount the interest alone supports.

Withdrawal math surprises everyone the first time. People divide balance by withdrawal and stop, ignoring that interest keeps working while the balance shrinks. The interest is worth years of extra runway, which is exactly what this calculator quantifies.

How to Use This Calculator

Enter the current balance, the monthly withdrawal you need, and the APY the remaining balance earns. The calculator returns years funded and the interest-only sustainable withdrawal.

The Withdrawal Formula

Each month the balance earns interest, then the withdrawal leaves. The formula solves for when the balance hits zero. If the withdrawal is smaller than one month’s interest, the balance never depletes: the principal funds you forever, which the calculator flags as 100+ years.

This is the amortization formula in reverse: a loan amortizes debt to zero with payments, savings amortize to zero with withdrawals. The same math prices both, which is why our loan amortization calculator feels familiar.

Worked Example

$250,000 balance, $1,500 monthly, 4 percent APY. Monthly rate = 1.04^(1/12) - 1 = 0.3274 percent. Months = ln(1500 / (1500 - 0.003274 x 250000)) / ln(1.003274) = ln(2.2009) / 0.003268 = 241.4 months = 20.1 years. Total withdrawn = $1,500 x 241.4 = $362,100, which exceeds the starting balance because interest funded the difference.

Sustainable version: interest-only withdrawal = $250,000 x 0.3274% = $818.65/month, lasting forever. Need $1,200 instead? Months = ln(1200/(1200-818.65))/0.003268 = ln(3.147)/0.003268 = 351 months = 29.3 years. Every $100 trimmed from the withdrawal buys roughly 2.5 extra years here. For inflation-adjusted retirement withdrawals, our retirement withdrawal calculator grows the payout yearly.

Stretching the Runway

The withdrawal rate dominates everything: at 4 percent APY, each $100 of monthly withdrawal costs about 2.5 years of runway on this balance. Before chasing yield, cut the withdrawal, because yield is uncertain and spending is a choice. And keep an emergency buffer outside this math; raiding the withdrawal fund for surprises is what breaks most plans. Our emergency fund calculator sizes that buffer.

The Bucket Strategy

Instead of one balance and one withdrawal, split savings into buckets: bucket one holds two years of withdrawals in cash, bucket two holds three to five years in bonds, bucket three holds the rest in growth assets. Spend from bucket one; refill it yearly from bucket two; refill two from three in good years. Market falls never force selling growth assets at the bottom, because the near-term spending sits in cash.

The bucket strategy is this calculator with psychology built in. The math is nearly identical to a blended portfolio, but retirees follow it better because the buckets make the plan visible: “two years of spending is safe no matter what the market does” calms nerves that a single number cannot. Rebalance yearly, keep bucket one full, and let buckets two and three do the growing. Behavior beats basis points.

Withdrawal Sequencing Across Accounts

Which account you draw from changes the math. Taxable accounts first lets tax-advantaged balances compound; Roth last preserves the tax-free growth longest. But rigid sequencing can spike you into higher brackets: sometimes blending traditional withdrawals to fill low brackets beats strict ordering. The optimal path fills each year’s lowest tax brackets first, whatever the account labels.

Required minimum distributions add a forced note at 73: traditional balances must start flowing whether you need them or not. Plan Roth conversions in the low-income years before RMDs begin to shrink the future forced withdrawals. The withdrawal calculator handles the spending arithmetic; a tax projection handles the sequencing. Run both yearly once RMD age approaches.

The Psychology of Drawing Down

Spending principal feels wrong after decades of saving: loss aversion makes every withdrawal hurt more than the math warrants. The reframe is purpose: the money was saved to be spent, and unspent savings are deferred life, not virtue. Planned withdrawals with a sustainable rate are the plan working, not the plan failing. Give yourself permission in advance, in writing.

Automate the withdrawals like you automated the savings: monthly transfers on a schedule, reviewed yearly. Manual withdrawals invite timing games and guilt spirals; automation makes spending as disciplined as saving was. The goal was never the biggest number at death; it was the best life the number could fund. Spend it well.

Estimates for planning only, not financial advice.