The Calculator Room
Every calculator here does one job properly: an answer the moment you type, the working shown so you can check it, and instructions written for someone who has never used it before. Homework, the job site, the kitchen table — pick a tool and go.
Showing all 40 calculators
Everyday Math
The ones you reach for without thinking — fast, forgiving and keyboard-friendly.
Basic Calculator
A full keypad with a running paper tape, memory keys and complete keyboard control.
OpenPercentage Calculator
Six percentage questions in one place — of, is-what-percent, increase, decrease, change and back-out.
OpenFraction Calculator
Add, subtract, multiply and divide fractions with exact answers, simplest form and the steps shown.
OpenTip & Bill Split
Tip, tax and an even split down to the cent — with a rounding mode so nobody hunts for coins.
OpenScientific & Algebra
Homework-grade horsepower: a real expression parser, exact algebra and full statistics.
Scientific Calculator
Types the whole expression at once — trig, logs, powers, roots, constants, DEG/RAD and memory.
OpenEquation Solver
Linear, quadratic, cubic and 2×2/3×3 systems — exact roots, complex answers and worked steps.
OpenMatrix Calculator
Add, multiply, transpose, invert and reduce matrices up to 5×5, with determinant and rank.
OpenStatistics Calculator
Paste a data set and get mean, median, mode, quartiles, deviation, outliers and a live histogram.
OpenGraphing & Plotting
Draggable, zoomable canvases that draw the maths while you type it.
Graphing Calculator
Plot up to four functions at once, drag to pan, scroll to zoom, and trace values along the curve.
OpenPolar & Parametric Plotter
Roses, spirals, Lissajous figures and cycloids — polar r(θ) and parametric x(t), y(t) curves.
OpenScatter Plot & Regression
Drop in x,y pairs and fit a line, parabola, power, exponential or log model with R².
OpenDerivative & Integral Explorer
See the slope and the area move: tangent lines, derivative curves and Simpson-accurate integrals.
OpenGeometry
Every answer comes with a drawing, because a shape you can see is a shape you can check.
Triangle Solver
Give any three parts — SSS, SAS, ASA, AAS or SSA — and get every side, angle, area and a scale drawing.
OpenArea & Volume Calculator
Twenty shapes and solids — area, perimeter, surface area and volume, each with a live diagram.
OpenCircle Calculator
Enter any one of radius, diameter, circumference or area — then arcs, sectors and chords too.
OpenDistance, Slope & Midpoint
Two points give you distance, slope, midpoint and the line in every form — plotted on a grid.
OpenConstruction
Job-site maths in the units you actually order in — with waste factored in and costs totalled.
Concrete Calculator
Slabs, footings, columns, stairs and tubes — cubic yards, cubic metres and the exact bag count.
OpenLumber & Board Feet
Board feet, linear feet, stud and joist counts for a wall or floor, plus the price of the pile.
OpenRoofing Calculator
Pitch to angle, footprint to true roof area, squares of shingles, underlayment and ridge cap.
OpenStair Calculator
Code-aware rise and run from a single floor-to-floor height, with a stringer layout drawing.
OpenHome & DIY
How much to buy, how many boxes that is, and what it lands at on the receipt.
Paint Calculator
Room by room: wall area minus doors and windows, coats, ceiling and trim, in gallons or litres.
OpenFlooring & Tile Calculator
Square footage, waste allowance, boxes to buy, grout lines and the total cost of the floor.
OpenMulch, Soil & Gravel
Depth × area in cubic yards, bags or tonnes — for mulch, topsoil, gravel, sand and stone.
OpenDeck Calculator
Decking boards, joists, beams, posts, screws and footings for a rectangular deck — with cost.
OpenMoney & Finance
Standard amortisation and compounding maths, with the schedule and the chart you need to trust it.
Loan Payment Calculator
Monthly payment, total interest and a full amortisation schedule for any term and rate.
OpenMortgage Calculator
Principal, interest, tax, insurance and HOA — plus what an extra payment each month really saves.
OpenCompound Interest
Watch a starting balance and regular contributions grow, with inflation-adjusted value shown.
OpenSavings Goal Planner
Name a target and a date and it solves for the deposit — or tells you when you will get there.
OpenHealth & Fitness
Published formulas, stated by name, in metric or imperial — estimates, never medical advice.
BMI Calculator
Body mass index with the category scale drawn out, plus the healthy weight range for your height.
OpenCalorie & TDEE Calculator
Mifflin-St Jeor BMR, activity-adjusted daily calories, and targets for losing or gaining weight.
OpenRunning Pace Calculator
Solve pace, time or distance, convert min/km to min/mile, and print a race split table.
OpenHeart Rate Zones
Five training zones from your max and resting heart rate, using the Karvonen reserve method.
OpenScience & Engineering
Conversions and physical laws, with the working shown so you can put it on a lab report.
Unit Converter
Twelve families and 130+ units — length, mass, volume, temperature, energy, pressure, data and more.
OpenMolar Mass Calculator
Type a formula like Ca(OH)2 and get molar mass, percent composition and moles ↔ grams.
OpenOhm's Law Calculator
Any two of volts, amps, ohms and watts give the other two — plus a resistor colour-code reader.
OpenProjectile Motion
Launch angle and speed give range, peak height and flight time, drawn as an animated trajectory.
OpenTime & Dates
Calendar arithmetic that gets leap years, weekends and holidays right so you do not have to count.
Date Difference
Days between two dates in years, months, weeks and hours — or add and subtract from a date.
OpenAge Calculator
Exact age in years, months and days, your next birthday, and every milestone along the way.
OpenTime Duration & Timesheet
Add and subtract clock times, total a week of shifts with breaks, and get decimal hours for payroll.
OpenBusiness Day Calculator
Working days between dates or N business days from today, skipping weekends and holidays.
OpenHow these work
Everything runs inside your browser. Nothing you type is uploaded, stored or shared — close the tab and it is gone. Once a page has loaded it keeps working with the connection off, which is the point on a job site or a school bus.
The formulas each calculator uses are printed on its own page, named and written out, so you can check the method as well as the number. Where a result is an estimate — health figures, material waste, anything depending on local code or local prices — the page says so plainly.
All calculators, layouts and instructions are © 2026 TutorTurbo.com.