How this 401(k) growth calculator 2026 works
Model: each month balance × (1 + return/12) + (your % + match %) × salary ÷ 12, assuming flat salary (raises accelerate the final number). Match math: '50% up to 6%' = employer adds 0.5 × your contribution on the first 6% of salary, so a 4% deferral gets 2%, 6%+ gets the full 3%. Taxes ignored: traditional 401(k) withdrawals are ordinary income (plus 10% penalty before 59½); Roth balances shown are the pre-tax-growth equivalent. Required minimum distributions start at age 73 under SECURE 2.0.
Frequently asked questions
What is the 401(k) contribution limit for 2026?
Employee deferrals: $24,500 per year, plus an $8,000 catch-up if you're 50 or older (and a $11,250 super catch-up at ages 60–63). The employer match doesn't count against this — the combined limit (415(c)) is $72,000. We flag when your input exceeds the deferral cap.
How much should I contribute to get the full match?
Always at least the match cap — it's instant 50–100% return on those dollars. A '50% up to 6%' formula means you leave money on the table contributing less than 6% of salary; at $80k that's up to $2,400/year of free money.
Is 7% a reasonable return assumption?
The S&P 500's nominal average is ~10%; a 60/40 stock/bond portfolio has returned ~7–8%. After inflation, plan on 4–5% real. The calculator compounds monthly, so year-one volatility is averaged away — treat the result as a center of a wide cone, not a promise.