After-Tax Engineering

Calculator · Stage 1

HSA Long-Term Compounding Calculator

Model the value of investing your HSA balance and paying medical expenses out of pocket. Compare HSA to taxable account to see the triple-tax advantage in dollars.

Educational tool only. Verify HSA contribution limits at IRS.gov each year.

HSA Inputs

2026 family limit: $8,750. Single: $4,400.

Receipts saved for future reimbursement.

Tax Rates

HSA Ending Value

HSA ending balance
Total receipt bank (reimbursable)
Available for non-medical (age 65+)

HSA vs Taxable Account Comparison

Same annual investment amount after tax. Taxable account pays dividend drag + LTCG on exit.

HSA (triple tax-free)
Taxable account (after exit tax)
HSA advantage

Annual Contribution Tax Savings

Tax saved per year (deduction)
Total tax saved over period

Assumptions

· HSA: contributions grow tax-free, withdrawals for medical are tax-free

· Taxable: after-tax contribution (reduced by marginal rate), 0.25% annual drag, LTCG on exit

· Receipt bank: out-of-pocket medical receipts saved for future reimbursement

· No state tax modeled · NIIT not included