Financial Decision Lab
Understand your retirement money by experimenting with it.
Gleefund is a practical toolkit for US retirement-account decisions. Get clear explanations, side-by-side comparisons, and interactive calculators for your 401(k), IRA, and Roth IRA — all running privately in your browser.
Start experimentingStart with a calculator
More 401(k) tools
401(k) Loan Calculator
What does a 401(k) loan really cost? See monthly payments, total interest, and the opportunity cost of borrowing.
Early Withdrawal Calculator
What does an early 401(k) withdrawal really cost after penalties and taxes? See your net take-home amount.
401(k) Growth Calculator
Project your 401(k) balance over time. See how contributions, employer match, and compounding grow your money.
Withdrawal Duration Calculator
How long will your retirement savings last? Estimate how many years your balance can sustain a given annual withdrawal.
2026 Contribution Limits
401(k), IRA, 403(b), and 457(b) contribution limits for 2026, including catch-up and super catch-up.
401(k) vs Roth IRA
Which should you prioritize? Compare contribution limits, employer match, tax treatment, and withdrawal rules.
IRA & Roth IRA decisions
Roth vs Traditional IRA
Which is better for your tax situation? Compare future values side-by-side and see which wins based on your current and future tax rates.
401(k) vs IRA
What's the difference and which should you prioritize? Compare contribution limits, rules, and tax treatment.
Roth Conversion Calculator
Should you convert Traditional IRA funds to Roth? Calculate the tax cost, break-even point, and long-term benefit.
Backdoor Roth IRA
What is a Backdoor Roth IRA and how does it work? A step-by-step guide with the pro-rata rule explained.
Mega Backdoor Roth
What is a Mega Backdoor Roth? See how after-tax 401(k) contributions can supercharge your Roth savings.
Learn the basics
What Is a 401(k)?
A plain-English guide to 401(k) plans: how they work, contribution limits, employer match, and tax benefits.
What Is a Roth IRA?
What makes a Roth IRA different? Tax-free growth, tax-free withdrawals, and income limits explained.
What Is an IRA?
The basics of Individual Retirement Arrangements: types, contribution limits, and how to choose.
Rule of 55
Can you withdraw from your 401(k) at age 55 without the 10% penalty? The Rule of 55 explained.
457 vs 401(k)
What's the difference between a 457(b) and a 401(k)? The key difference: no early withdrawal penalty on 457(b).