Money
Split bills, calculate, and keep things fair.
StaySplit
Split lodging costs fairly when people stay different nights (optional fixed fee).
Prorated rent calculator
Calculate prorated rent for moving in/out mid-month (multiple methods).
Unit price calculator
Compare deals by unit price (per g/ml/piece) so you can pick the best value fast.
Tip + tax bill splitter
Split a bill with tax + tip. Even split or itemized per person, with clean rounding.
Commute cost calculator
Estimate your commute cost per day/month/year: fuel or transit + time (optional time value).
Inflation calculator
Inflation-adjust money using a simple annual rate (compound). Shareable, browser-only MVP.
Stacked discount calculator
Calculate the real final price when multiple % discounts stack, plus a coupon and tax. Shareable, browser-only.
Percent change calculator
Compute percent change (A→B), reverse a percent change, and combine two-step percentage changes. Shareable, browser-only.
Weighted average calculator
Compute a weighted average from multiple (value, weight) pairs. Useful for grades, average cost basis, and more. Shareable, browser-only.
Break-even point calculator
Compute break-even units and revenue from fixed costs, variable cost per unit, and selling price. Includes an optional target-profit goal. Shareable, browser-only.
Salary ↔ hourly rate converter
Convert annual salary to hourly rate (and back) using your hours/week and weeks/year. Shareable, browser-only.
Take-home pay calculator (simple)
Estimate net (take-home) pay from gross pay using a simple tax rate and deductions. Shareable, browser-only MVP.
Electricity cost calculator
Estimate an electricity bill from kWh, rate per kWh, and fixed fees. Shows per-day cost with optional billing days. Shareable, browser-only MVP.
Loan amortization calculator
Compute payment per period and generate an amortization schedule (monthly or weekly) with total interest. Shareable, browser-only MVP.
Compound interest calculator
Estimate future value with a fixed annual rate and regular contributions (weekly/monthly/yearly). Shareable, browser-only MVP.
Mortgage affordability calculator
Estimate how much house you can afford using income, monthly debts, down payment, rate, and term. Uses simple DTI guidelines. Shareable, browser-only MVP.
Loan refinance calculator
Compare your current loan vs a refinance: payment, total interest, monthly savings, and break-even months (with fees). Shareable, browser-only MVP.
Savings rate calculator
Calculate your savings rate from income and expenses. Shows net vs gross definitions, savings amount, and a target gap. Shareable, browser-only MVP.
Emergency fund calculator
Emergency fund calculator: monthly essential expenses × target months → goal. See the gap and estimate months to reach it (optional interest). Shareable, browser-only MVP.
VAT calculator
Add VAT to net price, or remove VAT from gross price. Shows net, VAT amount, gross, and the multiplier. Shareable, browser-only MVP.
50/30/20 budget calculator
Split your income into needs (50%), wants (30%), and savings (20%). Enter current spending to see targets and gaps. Shareable, browser-only MVP.
Rent vs buy calculator
Compare renting vs buying a home with a simple cost model: rent growth, mortgage, taxes, maintenance, appreciation, and selling costs. Shareable, browser-only MVP.
IBAN validator
Validate and format an IBAN locally (checksum + basic structure). Copy the formatted IBAN or share a link. Browser-only MVP.
Luhn checker
Validate numbers with the Luhn algorithm (credit cards, IMEI, etc.). Also calculate the check digit. Browser-only; copy results or share a link.