FolioMath — portfolio & stock calculators

Free tools for portfolio allocation, rebalancing, gain/loss, average cost, shares, and percentage math. JavaScript is required for the interactive calculators.

Portfolio calculator — shares and price to % of total; target % to buy
Percentage calculator — % of total; part → %; % change
Shares calculator — dollars to shares; shares to dollars
Gain / loss calculator — cost vs current → return %
Dividends calculator — yield % or income from shares
Average cost calculator — multiple buys → average price
Rebalance calculator — buy or sell to target %
Mortgage calculator — payment or refinance comparison
Compound interest calculator — lump sum or monthly savings → future value
Discount & VAT calculator — sale price or net ↔ gross tax
Hourly rate calculator — annual ↔ hourly; hours × rate gross pay
Tip & split bill calculator — tip on a check or split a total evenly
Inflation calculator — future cost or today’s purchasing power (constant rate)
Loan comparison calculator — two loans; payment and interest vs the other
Fuel economy calculator — L/100 km, MPG, or trip fuel cost
Dividend withholding calculator — net dividends after a flat %
Safe rebuy calculator — buy back shares after partial sale; profit protection at floor price

Not financial advice.