US calculators

Full PITI payment, PMI, amortization schedule and extra-payment savings.

Growth chart, regular contributions, compounding frequency and inflation-adjusted real value.

Per-state sales-tax engine, trade-in tax credit, negative equity and 2026 rates by credit score.

Payment, total interest, amortization with CSV export, and an extra-payment payoff savings mode.

Preset percentages, per-person bill splitting and round-up, with US tipping norms.

Employer-match modeling, today's-dollars projection, growth chart and 2026 IRS limits.

Official CPI-U series 1913–2026: equivalent dollar value, cumulative and annualized inflation, chart.

Average effective rate by state for 2026, homestead exemptions, monthly escrow and your state's median bill.

Project savings to a future value, or set a goal and find the monthly amount needed, with a growth chart.

Lump sum plus monthly or yearly contributions, inflation-adjusted real value, two-scenario compare and a downloadable schedule.

Melt value of gold, silver and platinum by weight, karat and editable spot price, with dealer payout % and price per gram by karat.

2026 federal brackets with a per-bracket breakdown, marginal vs effective rate and filing-status comparison.

Salary or hourly take-home pay after federal, FICA and state tax, with a full per-paycheck breakdown.

Auto-fills the 2026 rate by state, reverses tax from a total, and splits state vs local.

Five modes on one page with the working shown for your exact numbers — no Calculate button.

Weighted and unweighted GPA side by side on the 4.0 scale, with unlimited courses.

Add, subtract, multiply or divide fractions with the steps shown and the answer simplified.

Weighted course grade and letter, plus the exact grade you need on the final to reach your target.

Visual WHO gauge, your healthy weight range in lb and kg, and how far you are from it.

BMR and daily calories via Mifflin-St Jeor, goal-based targets and a macro breakdown.

US Navy method with ACE category gauge, plus fat and lean mass in lb and kg.

Devine, Robinson, Miller and Hamwi in lb and kg, the Peterson equation, and your healthy BMI range.

Room-by-room builder that totals any shapes, with waste factor, material cost and ft²/yd²/m²/acres.

Slabs, footings, walls and columns in cubic yards, 40/60/80 lb bag counts, 10% overage and cost — multi-element total.

Footprint and pitch to true roof area, roofing squares and shingle bundles, with live slope factor, waste, material cost and a roof diagram.

Exact years, months and days, age in every unit, birth weekday and next-birthday countdown.

Weekly time card with break deduction, overnight shifts, automatic overtime and pay.

Days, weeks, months and years between two dates at once, with true business days and an exact breakdown.

Add or subtract years, months, weeks and days — or business days — from a date, with the result weekday, 30/60/90 presets and .ics export.