🧮Calculators
Calculators cover finance, health, math, physics, engineering and everyday life: interest and loans, net salary, BMI, rule of three, conversions and more. Results are informational and educational — for important decisions, confirm with a professional and official sources.
2826 tools
Dew Point Calculator
Compute dew point from temperature and relative humidity (Magnus formula).
Heat Index Calculator
Compute heat index from temperature (°C) and relative humidity (NOAA, valid for T ≥ 27°C).
Speed of Sound in Air
Compute speed of sound in air: v = 331.3 + 0.606·T (m/s).
Reynolds Number Calculator
Compute Reynolds number Re = ρ·v·D/μ.
Pearson Correlation Coefficient
Compute Pearson correlation coefficient r between X and Y lists.
Coefficient of Variation
Compute coefficient of variation CV = σ/μ × 100%.
Binomial Distribution
Compute P(X = k) and P(X ≤ k) in binomial distribution B(n, p).
Poisson Distribution
Compute P(X = k) and P(X ≤ k) in Poisson(λ).
Normal Distribution PDF/CDF
Compute Normal(μ, σ) PDF and CDF at a point.
Numerical Derivative
Compute numerical derivative f-prime(x) by central difference for a simple function.
Trapezoid Integral
Approximate ∫ₐᵇ f(x)dx by composite trapezoid rule.
Newton-Raphson Method
Find roots of f(x)=0 by Newton-Raphson with numerical derivative.
Bisection Method
Find a root of f(x)=0 in [a,b] by bisection (requires sign change).
Linear Regression (Least Squares)
Fit y = a·x + b by least squares; reports slope, intercept, R².
PMT Loan Payment Calculator
Compute fixed loan payment PMT = PV·i / (1−(1+i)^(−n)).
Present / Future Value
Convert between PV and FV: FV = PV·(1+i)ⁿ.
Kepler Orbital Period
Compute orbital period T = 2π√(a³/GM) from semi-major axis (m) and central mass (kg).
Carnot Efficiency
Compute Carnot efficiency η = 1 − T_cold/T_hot. Temperatures in Kelvin.
Point Charge Electric Field
Compute |E| = k·|Q|/r² for a point charge at distance r in vacuum.
Buoyancy (Archimedes)
Compute buoyancy force E = ρ·V·g for a submerged body.
ICMS (Brazilian VAT) Calculator
Compute Brazilian ICMS by inside-the-price: ICMS = base × rate / (1 − rate).
ISS (Brazilian Service Tax) Calculator
Compute Brazilian ISS service tax from gross value and municipal rate.
Lawyer Fees Calculator (Brazil)
Compute lawyer fees as % of case value with IR (1.5%) and optional ISS deductions.
Pro-Rata Rent Calculator
Compute pro-rata rent for partial months (move-in/out). Rent × days/month.
13th Salary Pro-Rata
Compute Brazilian 13th salary pro-rated by months worked (15+ day fraction counts as full month).
FGTS Severance Penalty
Compute Brazilian FGTS severance penalty (40% no fault, 20% mutual agreement).
Brazilian Rental Income Tax (Individual)
Compute Brazilian rental income tax for individuals using progressive monthly table.
Monetary Correction Calculator
Apply accumulated index (IPCA, INPC, IGP-M) percentage to a base value.
Late Payment Interest + Penalty
Compute late payment interest (simple per day) plus fixed penalty.
SAC Amortization Schedule
Generate SAC amortization schedule (decreasing payments with constant principal).
Price Amortization Schedule
Generate Price amortization schedule (fixed payments) with interest/principal split.
Retirement Projection
Project retirement savings with monthly contribution and monthly rate; shows final balance and lifetime monthly income.
Monthly Savings Goal
Compute monthly savings needed to reach a target in N months given monthly interest rate.
Savings vs CDI Comparison
Compare Brazilian savings vs CDB earning X% of CDI/Selic.
Total Cost of Ownership Calculator
Sum Total Cost of Ownership: purchase + monthly maintenance × months + variable costs.
ROE / ROA Calculator
Compute ROE = profit/equity and ROA = profit/assets.
CAC Payback Calculator
Compute CAC payback in months = CAC / monthly ARPU.
Cohort Retention Calculator
Compute cohort retention rate by month.
Conversion Funnel Calculator
Compute step-to-step conversion rates and overall % through a funnel.
Cylinder Moment of Inertia
Compute solid cylinder moment of inertia I = ½·m·r².
Sphere Moment of Inertia
Compute solid sphere (I = 2/5·m·r²) or hollow shell (I = 2/3·m·r²) moment of inertia.
Parsec ↔ Light-year
Convert distances between parsecs, light-years, AU and km.
Redshift z → velocity (Doppler)
Compute radial velocity from redshift z (non-rel for z<0.1, relativistic above).
Apparent vs Absolute Magnitude
Compute absolute magnitude M from apparent m and distance, or vice versa (parsecs).
Osmotic Pressure
Compute osmotic pressure π = M·R·T using R=0.0821 L·atm/mol·K.
Radioactive Half-life
Compute remaining amount A = A₀·(1/2)^(t/T) for radioactive decay.
Terminal Velocity
Estimate terminal velocity v = √(2mg/(ρ·A·Cd)).
Mach Number from Temperature
Compute local sound speed from temperature and Mach number M = v/a.
Drag Coefficient (Cd)
Compute drag coefficient Cd = 2F/(ρ·v²·A).
Poisson Ratio (ν)
Compute Poisson ratio ν from transverse and longitudinal strains.
Shear Stress Calculator
Compute shear stress τ = F/A. Output in Pa, kPa and MPa.
Light Travel Time
Compute light travel time across a distance (km, AU, light-years).
π Estimation (Monte Carlo)
Estimate π by Monte Carlo: 4 × (points inside unit circle / total).
Spearman Correlation (ρ)
Compute Spearman rank correlation ρ between X and Y lists.
Median and Quartiles
Compute min, Q1, median, Q3 and max with linear interpolation.
Outlier Detection (IQR Rule)
Detect outliers using IQR rule (outside Q1−1.5·IQR or Q3+1.5·IQR).
Z Table (Normal CDF)
Compute P(Z ≤ z) and P(|Z| ≤ z) for the standard normal distribution.
eGFR Calculator (CKD-EPI 2009)
Compute estimated GFR by CKD-EPI 2009 from serum creatinine, age, sex and race.
Body Surface Area (Mosteller)
Compute BSA by Mosteller formula: BSA = √(h·w/3600).
Pediatric Dose (Clark Rule)
Compute pediatric dose by Clark Rule: child = (weight_lb / 150) × adult dose.