Tool
Universal Calculator
26 calculators in one app: classroom scientifics, graphers, finance, trades and engineering. Free, no sign-up.
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26 of 26
Everyday classics
Two-line natural-display scientific with fractions, tables and an equation solver.
f(x) = sin(30°) + 2/3 - √8 = 1.1667
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Everyday classics
Classroom scientific with a two-line display, fractions, probability and angle modes.
3_1/2 + 5/8 = 4_1/8 | 10 nCr 3 = 120
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Everyday classics
Minimalist pocket four-function calculator with memory and percent.
1,977 × 1.0825 = 2,140.10
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Everyday classics
WriteView scientific with textbook entry, fractions and statistics.
D.A.L. Entry: 3 × (4 + 5) ÷ 2 = 13.5
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Graphing
Colour graphing calculator: Y= editor, tables, trace and regressions.
Y₁ = sin(x) | r₁ = 2·cos(3θ) | X₁ᴛ = 3cos(t), Y₁ᴛ = 3sin(t)
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Graphing
Computer-algebra system: symbolic solve, factor, derivatives and integrals.
d/dx[x²·sin(x)] = 2x·sin(x) + x²·cos(x) | factor(x² - 9)
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Graphing
Colour grapher with 3D surfaces and conic sections.
z = sin(√(x² + y²)) | (x-h)²/a² + (y-k)²/b² = 1
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Graphing
Advanced grapher for implicit curves and shaded inequalities.
x³ + y³ - 3xy = 0 | y ≥ x² - 4 ∧ x + y ≤ 2
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Graphing
RPL engineering grapher with slope fields for differential equations.
dy/dx = x - y | y_{n+1} = y_n + (h/6)(k₁ + 2k₂ + 2k₃ + k₄)
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Graphing
Modern grapher with animated sliders and curve fitting.
y = a·sin(bx - c) + d | y = mx + b (R² = 0.998)
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Trades & shop
Shop calculator for speeds and feeds, bolt circles, threads and trig.
RPM = (SFM × 3.82) / Tool Diam | IPM = RPM × IPT × Teeth
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Finance & business
Finance calculator for TVM, cash flows, NPV/IRR and amortization.
NPV = CF₀ + ∑ [CFₜ / (1 + r)ᵗ] | CPT PMT
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Trades & shop
Electrical calculator for Ohm's law, voltage drop and NEC wire sizing.
VD = (2 × K × I × L) / CM | %VD = (VD / V) × 100
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Trades & shop
Pipefitting calculator for rolling offsets, take-outs, miters and pipe schedules.
True Offset = √(Roll² + Set²) | Travel = True Offset / sin(θ)
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Trades & shop
Feet-inch-fraction maths, rafters, stairs and board feet.
Diagonal² = Rise² + Run² | Pitch = Rise / Run
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Trades & shop
Duct sizing, airflow and BTU load calculations.
CFM = Area × FPM | Dₑ = 1.30 × (a·b)⁰·⁶²⁵ / (a+b)⁰·²⁵
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Science & engineering
Flight computer for wind triangle, fuel, time and density altitude.
GS = √(TAS² - Crosswind²) ± Headwind | CG = ∑Moments / ∑Weight
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Finance & business
RPN financial calculator with a TVM solver and amortization.
PMT = (PV·r(1+r)ⁿ) / ((1+r)ⁿ - 1)
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Finance & business
Office desk calculator with tax, cost/sell/margin, GT and a paper tape.
Margin % = (Sell − Cost) / Sell × 100
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Science & engineering
Natural-display scientific with trig, fractions and engineering notation.
f(x) = sin(θ) + ln(x) / √y
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Science & engineering
Touch 2D function plotter with a matrix tab.
Y₁(x) = sin(x) · e^(-0.1x)
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Software
64-bit integer calculator with HEX/DEC/OCT/BIN and a clickable bitboard.
HEX: 0xDEADBEEF ↔ BIN: 1101...1111
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Trades & shop
Quick speeds and feeds, bolt circle and right-angle trig.
RPM = (SFM × 3.82) / D
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Trades & shop
Pipe flow, Reynolds number, head loss and hydraulic cylinders.
hf = f · (L/D) · (v² / 2g) | HP = (PSI × GPM) / 1714
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Science & engineering
Mechanics, projectiles, thermodynamics and relativity solvers.
R = (v₀² sin 2θ) / g | PV = nRT | γ = 1 / √(1 - v²/c²)
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Science & engineering
Colour conversion, WCAG contrast, Delta E and palettes.
CR = (L1 + 0.05)/(L2 + 0.05) | ΔE₀₀ CIEDE2000
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Reference
What's inside
Independent implementations built for touch and keyboard. Every calculation runs in your browser.
Faithful key layouts
Each classic is a clean-room recreation of how its keys and display behave: two-line natural display, SHIFT and ALPHA layers, RPN stacks and worksheet modes.
Graphing and algebra
Plot functions, polar and parametric curves, slope fields and 3D surfaces with touch pan and zoom. Solve, factor, differentiate and integrate symbolically.
Finance
Time value of money, cash flows with NPV and IRR, amortization schedules, and a commercial desk calculator with tax, cost/sell/margin and grand total.
Trades and shop floor
Speeds and feeds, bolt circles, thread tables, feet-inch-fraction maths, rafters and stairs, NEC wire sizing, pipe offsets and duct sizing.
Science and engineering
Fluid flow and head loss, projectiles and kinematics, gas laws and relativity, flight computer maths, colour science and a 64-bit programmer mode.
Paper tape, sound and Android
Every result can go to a paper tape you can copy. Key clicks and vibration are optional and remembered. The Android APK is a standalone app that runs without a connection.