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GoModo US
100% Free • No Sign-up • Zero Server Data Storage

Everyday Math & Finance,
Reimagined for Speed & Clarity.

Calculate federal and state taxes on multimillion-dollar Powerball jackpots, estimate take-home pay, and convert imperial-metric units seamlessly. Instant, responsive, and privacy-focused online web tools.

Featured US & Global Tools

New tools added regularly
FIRE & 4% Rule

Compound Interest & Wealth Growth Simulator

Simulate stock market and ETF compounding with monthly contributions, annual return presets (S&P 500, NASDAQ, Treasuries), inflation purchasing power adjustments, and 4% FIRE retirement monthly withdrawals.

Monthly Contribution Compounding Full Amortization Schedule Inflation Adjusted Today's $ Taxable vs Roth IRA / 401(k) FIRE 4% Rule Monthly Payout
Calculate Compound Growth
Live FRED Rates

Mortgage & PITI Payment Calculator

Comprehensive US fixed-rate mortgage calculator with live Federal Reserve (FRED) benchmark rates, complete PITI payment breakdown (Principal, Interest, Taxes, Insurance, PMI), and full 30-year amortization schedule.

30-Yr & 15-Yr Fixed Live FRED Benchmark (7.32%) PITI Breakdown & PMI Annual Amortization Table
Calculate Mortgage Payments
IRS Tax Estimator

Powerball & Mega Millions Tax Calculator

Calculate exact net take-home payouts after federal (24% upfront + 37% top bracket) and state taxes for all 50 states. Compare Lump Sum Cash Option vs 30-Year Annuity with annual 5% escalation.

Cash vs 30-Yr Annuity 50 States + DC Tax Rates 0% Tax States (CA, TX, FL) Federal 24% + 13% Gap NYC & Local Surtax
Calculate Lottery Taxes
Fair Bill Split

Dining Tip & Fair Bill Splitter

Smart US restaurant tipping calculator with standard 15%, 18%, 20%, 25% presets, pre-tax vs post-tax calculation toggles, and fair group split options with copyable share text.

15% - 25% Tip Presets Pre-tax / Post-tax Option Equal Bill Splitting One-Click Summary Copy
Calculate Dining Tips
Metric ↔ US Customary

Everyday US Unit Converter

Effortlessly switch between US Imperial and Metric systems: Pounds (lbs) to kg, Miles/Feet/Inches to km/m/cm, Fahrenheit (°F) to Celsius (°C), and Gallons/Fluid Ounces to Liters/mL.

lbs ↔ kg / oz ↔ g mi ↔ km / ft & in ↔ cm °F ↔ °C Temperature gal ↔ L / fl oz ↔ ml
Convert Units Now

100% Client-Side Privacy

Your calculations never leave your computer. All formulas execute entirely within your browser's local JavaScript sandbox.

IRS & State Tax Compliance

Strictly updated to current 2026 federal brackets, 24% withholding regulations, and state-by-state lottery tax laws.

Zero Bloat, Blazing Fast

Lightweight static pages built without heavy frameworks. Loads instantaneously across iPhones, Android, Mac, and PC.

Frequently Asked Questions

Q. Are all tools on GoModo US completely free?
Yes. Every calculator, converter, and utility on GoModo is 100% free with no hidden fees, subscriptions, or credit card requirements.
Q. Is my entered financial information saved on your servers?
No. All math is performed entirely in your browser using client-side JavaScript. We do not transmit, log, or store any numbers or personal inputs on any server.
Q. How are Powerball and Mega Millions taxes calculated?
The lottery agency automatically withholds 24% for federal taxes upfront. When filing your annual IRS return, multimillion-dollar prizes reach the top 37% federal tax bracket, requiring an additional ~13% payment. Our calculator factors in this total federal liability plus individual state and local taxes for all 50 states.