System of Equations Calculator
Solve 2x2 or 3x3 systems of linear equations with Gaussian elimination, solution type, determinant, residual, and clear limits.
Interactive calculatorOpen calculatorMath & Education Calculators
Calculate arithmetic, scientific expressions, units, dates, algebra, physics, and education formulas with visible methods.
Available calculators
Choose a focused tool, keep the method and units visible, and compare scenarios without sending deterministic inputs to a calculation server.
Rocket Equation Calculator
Calculate ideal rocket delta-v from wet mass, dry mass, and specific impulse. See mass ratio, propellant fraction, exhaust velocity, formula, and limits.
Interactive calculatorOpen calculatorHomeschool GPA Calculator
Calculate credit-weighted homeschool GPA with entered 0–4 grade points and optional honors or advanced-course weight. See quality points and transcript cautions.
Interactive calculatorOpen calculatorBasic Calculator
Calculate arithmetic, percentages, percent change, division, and powers with a clear operation label and keyboard-friendly inputs.
Interactive calculatorOpen calculatorScientific Calculator
Evaluate bounded scientific expressions with functions, constants, powers, factorials, and explicit degree or radian mode—without JavaScript eval.
Interactive calculatorOpen calculatorUnit Converter
Convert length, area, volume, mass, temperature, speed, pressure, and decimal or binary data units with compatible-unit controls.
Interactive calculatorOpen calculatorDate Calculator
Find calendar days and weekdays between ISO dates, choose inclusive counting, or add a signed whole-day interval without daylight-saving drift.
Interactive calculatorOpen calculatorHow this shelf is organized
Deterministic by default
Arithmetic, dates, units, bills, discounts, and loan schedules run in the browser.
Assumptions stay nearby
Every result retains its operation, unit, rate, or model boundary.
External data is dated
When a tool requests reference data, freshness and cached state appear beside the input.