Tetra Calculator

Free Online Calculators

Tetra Calculator is a growing library of free, searchable calculators for practical questions, schoolwork, projects, planning, games, and everyday estimates in a great variety of topics. Each page includes a working calculator, visible formula or method notes, plain examples, assumptions, and limitations.

Calculator Categories

Top Calculators

CalculatorCategoryUse
Concrete CalculatorConstructionEstimate concrete volume for a slab and convert that volume into cubic feet, cubic yards, and common premix bag counts.
Cubic Feet CalculatorConstructionFind the volume of a box shape in cubic feet from length, width, and height in mixed units, with conversions to cubic yards, cubic meters, liters, and gallons.
Stair CalculatorConstructionLay out a straight staircase from the total rise, giving the number of risers and treads, exact riser height, total run, stair angle, and stringer length with IRC code checks.
Tile CalculatorConstructionEstimate tile count from room size, tile size, grout gap, and waste percentage.
Shape Poem GeneratorEducationTurn any poem into a concrete poem shaped like a heart, star, tree, and more.
Weighted Grade CalculatorEducationCalculate a weighted class grade from assignment scores and weights, then estimate the score needed on remaining work.
Ambigram GeneratorFunCreate a rotational two-name ambigram you can flip, preview, and download.
Baseball Player Name GeneratorFunCreate plausible fictional baseball player names with classic nicknames and position tags.
Discord Role Name GeneratorFunCreate themed Discord role names for ranks, rewards, permissions, and community identity.
Football Player Name GeneratorFunCreate plausible fictional American-football player names for rosters, stories, and games.
Gang Name GeneratorFunCreate invented noir crime-crew and syndicate names for fictional stories, games, and campaigns.
Love CalculatorFunGenerate a playful compatibility score from two names for entertainment.
Made-Up Words GeneratorFunCreate pronounceable invented words in English-like, fantasy, and short brandable styles.
Producer Name GeneratorFunCreate fictional music producer and beatmaker stage names matched to a selected genre.
Soccer Name GeneratorFunCreate fictional international player names or original soccer club names for rosters and stories.
Gamertag GeneratorGamesCreate compact gaming handles in clean, edgy, or retro styles from an optional seed word.
Pokemon Damage CalculatorGamesEstimate a Pokemon-style damage range from level, move power, attack, defense, STAB, type effectiveness, and modifiers.
Matrix CalculatorMathCalculate 2x2 and 3x3 matrix determinants, inverses, products, and reduced row echelon form.
Percentage Decrease CalculatorMathFind the percentage decrease between two numbers, reduce a value by a percentage, or recover the original value before a decrease, with each calculation written out.
Pythagorean Theorem CalculatorMathSolve a squared plus b squared equals c squared for any side of a right triangle, with the area, perimeter, and angles included.
Scientific CalculatorMathA free online scientific calculator for trigonometry, logarithms, powers, roots, factorials, combinations, and constants, with selectable degree, radian, and gradian angle modes, memory keys, and a calculation history.
Sig Fig CalculatorMathCount significant figures, highlight which digits count, and round numbers to a chosen number of significant figures.
100m Wind CalculatorSportsCalculate a zero-wind, sea-level estimate for a 100 m sprint. Check if the wind speed is wind-legal.
Business Days CalculatorTime DateCount business days between two dates or add business days to a start date with weekend, holiday, and custom-date exclusions.
Time Duration CalculatorTime DateCalculate elapsed time between two date-times with optional break minutes and decimal-hour output.
Work Time CalculatorTime DateAdd up hours worked across a week from daily start times, end times, and breaks, with totals in hours and minutes and in decimal hours.