AtlasCalcEngine directory ● v1.0 computational core
All calculators 85 tools
85 free precision engines across 16 curated categories. Verified against IEEE-754 standards.
Latency
<3.8ms
Telemetry
Zero
Client-side
100%
Showing 85 precision calculators
Determinant, inverse, transpose, and scalar multiplication of 2×2 matrices.
det = ad − bc; inv = (1/det)·[[d,−b],[−c,a]]
CalculateCalculate percentages, what-percent, and percent change.
result = base × (rate / 100)
Calculate- 🧮
Add, subtract, multiply, divide and simplify fractions.
a/b ± c/d = (a·d ± b·c) / (b·d); simplify by GCD
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Greatest common divisor and least common multiple of two numbers.
gcd(a,b) by Euclid: gcd(a,b) = gcd(b, a mod b); lcm(a,b) = (a·b) / gcd(a,b)
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math
Check if a number is prime, or list all primes up to N.
Trial division up to √n; or Sieve of Eratosthenes for ranges
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math
Mean, median, mode, range, variance, and standard deviation of a list.
mean = Σx/n; median = middle value; std = √(Σ(x − mean)² / n)
Calculate Solve for the unknown in a proportion a/b = c/d.
a/b = c/d → c = a·d / b
Calculate- 📈
math
Find the real roots of a linear (ax + b) or quadratic (ax² + bx + c) equation. Visualize the polynomial on a graph.
equation · polynomial · root
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finance
Find the final price after a percentage discount.
final = original × (1 − discount/100)
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finance
Monthly EMI, total interest, and total payment for a fixed-rate loan.
EMI = P × r × (1+r)ⁿ / ((1+r)ⁿ − 1)
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finance
Monthly mortgage payment with principal, interest, taxes, and insurance.
P = EMI × (1 − (1+r)⁻ⁿ) / r
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finance
Future value with compound interest and optional monthly contributions.
A = P × (1 + r/n)^(n·t)
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finance
Return on investment with annualized ROI.
ROI = (gain / cost) × 100; Annualized = (final/initial)^(1/years) − 1
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finance
Profit margin %, markup, and gross/net profit calculations.
margin = (revenue − cost) / revenue × 100; markup = (revenue − cost) / cost × 100
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finance
Break-even point in units and revenue.
units = fixedCosts / (price − variableCost)
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finance
Add or remove VAT / sales tax from a price.
VAT = net × rate/100; gross = net × (1 + rate/100); net = gross / (1 + rate/100)
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finance
Convert between yearly, monthly, and hourly, with tax deduction.
net = gross − tax − socialSecurity − otherDeductions
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finance
Adjusts a price for inflation between two years using an average annual rate.
realValue = nominalValue / (1 + inflation)^years; realReturn = ((1+nominal)/(1+inflation)) − 1
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finance
Estimate the nest egg you need to retire, and how much to save monthly.
needed = annualIncome × (1 − replacementRate) / (realReturn × years)
Calculate - 🪙
finance
Live spot price for top cryptocurrencies and portfolio value.
crypto · bitcoin · btc
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Live spot price for gold (XAU) or silver (XAG) per troy ounce, plus portfolio value.
gold · silver · xau
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finance
Live stock price, day change, and portfolio value.
stock · share · equity
Calculate - ❤️
health
Body Mass Index from weight and height (metric or imperial).
BMI = weight(kg) / height(m)²
Calculate - ❤️
health
Basal Metabolic Rate using Mifflin-St Jeor, with TDEE for activity.
Men: BMR = 10W + 6.25H − 5A + 5; Women: BMR = 10W + 6.25H − 5A − 161
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health
Body fat percentage using the US Navy circumference method.
US Navy: BF% = 86.010·log10(waist−neck) − 70.041·log10(height) + 36.76 (M)
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health
Ideal body weight using Devine, Robinson, and Miller formulas.
Devine: 50 kg + 2.3 kg per inch over 5 ft (M); 45.5 kg + 2.3 kg per inch over 5 ft (F)
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health
Recommended daily water intake based on weight, activity, and climate.
Daily water ≈ weight(kg) × 35 ml; +500 ml per 30 min of exercise
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health
Estimated due date from last menstrual period.
EDD = LMP + 280 days (Naegele's rule)
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health
Estimate ovulation day and fertile window from cycle dates.
Ovulation ≈ LMP + cycleLength − 14 days; fertile window = ± 5 days
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health
Maximum and target heart rate zones (Karvonen formula).
MHR ≈ 220 − age (estimate); Target HR = MHR × intensity%
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health
Estimated blood alcohol concentration using Widmark's formula.
BAC% = (alcohol_g / (weight_kg × r)) × 100 − 0.015 × hours
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fitness
Estimated 1-rep max from submaximal lifts.
Epley: 1RM = w × (1 + r/30); Brzycki: 1RM = w / (1.0278 − 0.0278r)
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fitness
Pace, finish time, and speed from distance and time.
pace = time / distance; speed = distance / time; pace = 60 / speed
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fitness
Estimate cycling speed from power, or required power for a target speed.
FTP ≈ 0.95 × 20-min max power; W/kg = power / weight
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fitness
Daily protein target based on body weight and goal.
g/day = weight(kg) × 0.8 to 2.2; 1.6–2.2 g/kg for muscle gain
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time
Calculate exact age in years, months, and days from a birthdate.
age = asOfDate − birthDate
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time
Days, weeks, months, and years between two dates.
days = (date2 − date1) / 86,400,000
Calculate - 📅
time
Number of business days (Mon–Fri) between two dates, excluding an optional holiday list.
business days = total days − (weekends + holidays)
Calculate - 📅
time
Convert between ms, seconds, minutes, hours, days, weeks, months, years.
seconds = hours × 3600 + minutes × 60 + seconds
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education
GPA from grades and credit hours. Format: 'A,4; B+,3; A-,4'.
GPA = Σ(gradePoints × credits) / Σ(credits)
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education
Convert a percentage score to a letter grade and GPA points.
Final grade → letter via institution's cutoff
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education
How many classes can you miss given an attendance policy?
attendance% = present / totalSessions × 100
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technology
Bitwise AND, OR, XOR, NOT, SHIFT and base conversions for binary.
binary to decimal: Σ(bit × 2^position)
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technology
Hexadecimal arithmetic, conversions to/from decimal, binary, and octal.
hex to decimal: Σ(digit × 16^position)
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technology
Convert a number between any two bases from 2 to 36.
value = Σ(digit × base^position)
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technology
IPv4 subnet breakdown from CIDR (e.g. 192.168.1.0/24).
hosts = 2^(32 − CIDR) − 2; network = IP AND mask
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technology
Generate strong random passwords with custom character sets.
random = crypto.getRandomValues(buffer)
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technology
Generate random integers in a range, dice rolls, or coin flips.
result = min + rand × (max − min + 1); crypto where available
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construction
Volume of concrete needed for slabs, footings, columns, or walls.
volume = length × width × thickness; bags = volume / 0.6 ft³ per 80-lb bag
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construction
Estimate bricks and mortar needed for a wall.
count = wallArea / brickArea; brickArea = (length + joint) × (height + joint)
Calculate - 🎨
construction
Estimate paint needed for walls, ceilings, or rooms.
area = perimeter × height; gallons = area / coverage; coverage ≈ 350–400 ft²/gal
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construction
Estimate planks/tiles needed to cover a room, with waste factor.
area = length × width + waste; waste = 5% (tile) to 15% (diagonal plank)
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construction
Tiles needed for a floor or wall (square or rectangular).
tiles = area / (tileLength × tileWidth); +10% for waste
Calculate - ⛽
automotive
Compute the cost of fuel for a trip given distance, consumption, and price.
cost = distance × (consumption / 100) × pricePerLiter
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automotive
Convert between L/100km, MPG (US), MPG (UK), and km/L.
L/100km = (fuel / distance) × 100; MPG(US) = mi / gal; L/100km = 235.215 / MPG(US)
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conversion
Convert between metric and imperial units of length/distance.
1 m = 3.28084 ft = 39.3701 in; 1 km = 0.621371 mi
Calculate - ⚖️
conversion
Convert between metric and imperial units of mass.
1 kg = 2.20462 lb; 1 lb = 453.592 g; 1 stone = 14 lb = 6.35029 kg
Calculate - 🌡️
conversion
Convert between Celsius, Fahrenheit, Kelvin, and Rankine.
F = C × 9/5 + 32; K = C + 273.15
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conversion
Convert between metric and imperial units of area.
1 acre = 43,560 ft² = 4,047 m²; 1 hectare = 10,000 m²
Calculate - 🧊
conversion
Convert between metric and imperial units of volume.
1 US gal = 3.785 L; 1 UK gal = 4.546 L; 1 m³ = 1,000 L
Calculate - 💨
conversion
Convert between m/s, km/h, mph, ft/s, and knots.
1 mph = 1.609344 km/h; 1 knot = 1.852 km/h; 1 m/s = 3.6 km/h
Calculate - 🌬️
conversion
Convert between Pa, kPa, bar, psi, atm, mmHg.
1 atm = 101.325 kPa = 14.696 psi = 760 mmHg = 1.01325 bar
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conversion
Convert between joules, kilojoules, kWh, calories, BTU.
1 J = 1 N·m = 1 W·s; 1 kWh = 3.6 MJ; 1 kcal = 4,184 J
Calculate - 📐
conversion
Convert between degrees, radians, gradians, arc-minutes, turns.
360° = 2π rad = 400 grad
Calculate - 📳
conversion
Convert between Hz, kHz, MHz, GHz, RPM.
1 GHz = 1,000 MHz = 10^9 Hz
Calculate - ⏱️
conversion
Convert between seconds, minutes, hours, days, weeks, years.
1 day = 24 h = 1,440 min = 86,400 s
Calculate - ⚡
engineering
Solve for voltage, current, or resistance using V = I × R.
V = I × R ⇔ I = V / R ⇔ R = V / I ⇔ P = V × I
Calculate - 🎛️
engineering
Read a 4-band resistor from its color bands.
R = (10·d1 + d2 + d3) × 10^multiplier (5-band adds a 3rd digit)
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engineering
Capacitor stored energy and RC time constant.
C_total (series) = 1 / (1/C1 + 1/C2 + ...); C_total (parallel) = C1 + C2 + ...
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engineering
Output voltage of a two-resistor voltage divider.
Vout = Vin × R2 / (R1 + R2)
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engineering
Compute electrical power from V, I, and R in any combination.
DC: P = V × I; AC single-phase: P = V × I × cos(φ)
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engineering
Combine resistors in series, parallel, or a custom mix.
Series: R = Σ Rᵢ; Parallel: 1/R = Σ 1/Rᵢ
Calculate - 💱
travel
Convert between world currencies using cached exchange rates.
converted = amount × exchangeRate
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travel
Estimate the fuel cost of a road trip.
cost = distance × (consumption / 100) × pricePerLiter
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science
Solve motion problems with constant acceleration.
v = u + at; s = ut + ½at²; v² = u² + 2as
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science
Newton's second law — solve for force, mass, or acceleration.
F = m × a (net force = mass × acceleration)
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science
Compute kinetic energy from mass and velocity.
KE = ½ × m × v²
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science
Convert between pH and hydrogen ion concentration.
pH = −log₁₀([H⁺]); [H⁺] = 10^(−pH)
Calculate - 🤖
science
Type what you want in plain language. The AI routes to the right calculator and pre-fills the values.
intent = parse(prompt) → bestCalculator(inputs)
Calculate - 🏷️
business
Convert between markup and gross margin.
markup = (revenue − cost) / cost × 100
Calculate - 🛍️
business
Apply a series of discounts in sequence (e.g. 20% then 10%).
final = original × Π(1 − dᵢ/100)
Calculate Compute the running cost of an electrical appliance.
energy = power × time; cost = energy × pricePerKwh
Calculate- 🖼️
Estimate wallpaper rolls needed to cover a room.
rolls = ceil(perimeter / rollWidth) × ceil(height / rollLength) + waste
Calculate - 🍳
daily
Calculate tip and split the bill among multiple people.
tip = bill × rate/100; total = bill + tip; perPerson = total / people
Calculate