🧮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
Sit-and-Reach (Flexibility) Calculator
Assess posterior chain flexibility via sit-and-reach. Compare your value with reference tables by gender and age.
Waist-Hip Ratio Calculator
Compute waist-hip ratio (waist ÷ hip) — cardiovascular risk indicator. Classifies low, moderate, high by gender.
BIA (Bioelectrical Impedance) Calculator
Estimate body fat % from electrical impedance (Z in ohms), weight, height, age, gender. Lukaski (1986) formula.
RMR (Resting Metabolic Rate) Calculator
Compute resting metabolic rate (kcal/day) using Mifflin-St Jeor — modern formula more accurate than Harris-Benedict.
Healthy Weight Range Calculator
Compute minimum healthy weight (BMI=18.5) and maximum recommended (BMI=24.9) for a height. Shows healthy range.
Pros & Cons Decision Maker
Evaluate a decision with weighted pros and cons (1-5). Compute final weighted balance and recommend (yes, no, undecided).
Virtual Race Pace Calculator
Estimate race pace (5K, 10K, 21K, 42K) from easy-training pace. Uses Daniels-VDOT approximation.
Pace ⇄ Time ⇄ Distance Calculator
Solve the triad pace (min/km), time (h:m:s) and distance (km). Provide any two and compute the third.
Multiplier (Proportion) Calculator
Given X of a quantity in Y total, compute multiplier for other quantities. For recipes, scaling, dosing.
Volumetric Weight Calculator
Compute volumetric weight: (L × W × H cm) / factor (5000 air, 6000 ground). Compare to actual weight.
Carbon Footprint (Trip) Calculator
Estimate CO₂ emissions from trips: car (gasoline, ethanol, diesel, electric), plane, bus. Inputs: distance and mode.
Monthly Carbon Balance Calculator
Compute monthly carbon balance: emissions (car, flights, electricity, food) minus offsets (trees, credits). In kg CO₂.
LED vs Incandescent Savings Calculator
Compute savings replacing incandescent with LED: kWh/year, $/year, payback. Inputs: lamps count and hours/day.
Savings vs CDB Comparison
Compare poupança vs CDB (% of CDI) over N months. Shows which yields more and the difference in $ and %.
CDB Multi-Scenario Calculator
Simulate CDB pre, post (% of CDI) and hybrid (IPCA + spread). With regressive IR. Final value and net yield.
LCI/LCA Calculator (no IR)
Simulate LCI (real estate) or LCA (agribusiness): % of CDI, term. Since IR-exempt, net = gross. Compares to equivalent CDB.
Treasury Prefixed Calculator (Brazil)
Simulate Treasury Prefixed: agreed annual rate, term to maturity. Applies regressive IR and shows redemption value.
Treasury IPCA+ Calculator
Simulate Treasury IPCA+: real annual rate + projected IPCA. Applies regressive IR. Shows real and nominal yield.
4-Way Investment Comparison
Compare 4 investments side-by-side: savings, CDB 100% CDI, LCI 95% CDI, Treasury Prefixed 11%. For a given value and term.
Time to Goal Calculator
Compute in how many months a monthly contribution + initial balance reaches a financial goal. With monthly interest rate.
Accessible Font Size Calculator
Compute minimum font size for WCAG 2.1 accessibility: AA (16px body, 24px heading), AAA (18.66px body, 36px heading). Configurable.
Substance Half-Life Calculator
Compute how long for a substance to leave the body (5 half-lives = undetectable). Caffeine, alcohol, nicotine, common drugs.
Generator Frequency Calculator
Compute generator output frequency (N poles × M rpm): f = (P × N) / 120. Hz output for Brazil (60) and Europe (50).
Cutoff Frequency Calculator (RC/RL/LC)
Compute cutoff frequency (-3dB) of passive filters: RC, RL, LC. For analog circuits.
Amplifier Gain (dB) Calculator
Compute amplifier gain in dB and voltage/power factor. dB = 20·log₁₀(V_out/V_in) = 10·log₁₀(P_out/P_in).
Cable Characteristic Impedance Calculator
Compute characteristic impedance Z₀ of cables: coaxial, twisted pair, microstrip. Z₀ = √(L/C). For impedance matching.
Coaxial Cable Loss Calculator
Compute total dB loss of a coaxial cable: length × attenuation per meter. For RF, specific frequency, cable type (RG-58, RG-213, etc.).
Monthly Poupança Yield Tracker
Compute month-by-month poupança yield showing accumulated balance per month. Visualize compound curve with monthly deposit.
Late Rent Interest+Penalty Calculator
Compute penalty (2% statutory) + interest (1% monthly) + IGP-M correction on late rent. Total due amount.
Stock Market Long-Term Yield Calculator
Simulate stock market long-term yield: initial + monthly contribution × N years × annual rate. Compares to fixed income.
Time to Lose Weight Calculator
Estimate time to lose X kg given a daily caloric deficit. Uses 7700 kcal per kg of fat. For health goals.
Credit Card Annual Fee Calculator (12x)
Compute credit card annual fee impact when paid in 12 installments. Shows monthly value and % of limit.
PayPal/PicPay Withdrawal Time Calculator
Estimate when money arrives in bank account from PayPal/PicPay balance. Considers business days and weekends.
Fixed Income vs Stocks (Long Term)
Compare growth of $X in fixed income (constant rate) vs stocks (vol simulated via stdev). N years.
Time to Pay Off Loan Calculator
Compute months to pay off a loan given balance, monthly rate, and monthly payment. Shows total interest.
Monthly Income from Capital Calculator
Compute approximate monthly income from invested capital, given net annual rate. Useful for "live off interest" planning.
FII (REIT) Yield Calculator
Compute monthly and annualized yield of a Real Estate Fund (FII): cota price × monthly dividend. Shows return vs CDI.
Stock Trade Profit Calculator
Compute profit/loss on stock buy/sell: buy price, sell price, qty, fees. 15% IR on profit.
Crypto Profit/Loss Calculator
Compute crypto profit/loss: buy price, current price, qty. 15% IR on profit above R$35k monthly sales.
Credit Card Interest Impact Calculator
Compute explosive effect of credit card revolving (12-15% monthly) on unpaid debt. Month-by-month growth.
Startup Runway / Burn Rate Calculator
Compute runway (months until cash zeroes) from current balance and monthly burn rate. Classic startup indicator.
Emergency Fund Calculator
Compute emergency fund target: monthly expenses × 6 (min) or × 12 (recommended). Considers inflation.
Clausius-Clapeyron Vapor Pressure
Estimate P2 with the simplified Clausius-Clapeyron equation from P1, T1, T2 and ΔHvap (J/mol).
Reaction Enthalpy
Compute ΔHrxn = ΣΔHf(products) − ΣΔHf(reactants) in kJ/mol.
Reaction Entropy
Compute ΔSrxn = ΣS°(products) − ΣS°(reactants) in J/(mol·K).
Gibbs Free Energy of Reaction
Compute ΔG = ΔH − T·ΔS (kJ/mol) for a reaction.
Spin-Only Magnetic Moment
Compute the spin-only magnetic moment µ = √(n(n+2)) in Bohr magnetons.
Lorentz Force
Compute the magnetic force F = q·v·B·sin(θ) on a moving charge.
Larmor Frequency
Compute the Larmor angular frequency ω = γ·B (rad/s).
Relativistic Time Dilation
Compute time dilation t' = t / √(1 − v²/c²) from Special Relativity.
Relativistic Total Energy
Compute total energy E = γ·m·c² (J) with γ the Lorentz factor.
Particle Angular Momentum
Compute the angular momentum L = m·v·r·sin(θ) of a particle.
Wavenumber
Compute the angular wavenumber k = 2π/λ (rad/m).
RGB Color Temperature
Estimate the correlated color temperature (Kelvin) of an RGB color via McCamy approximation.
Young Equation
Compute γSL = γSV − γLV·cos(θ) from Young's equation.
Jurin Capillarity
Compute capillary rise h = 2·γ·cos(θ)/(ρ·g·r) via Jurin's law.
Darcy-Weisbach Head Loss
Compute head loss hf = f·(L/D)·v²/(2g) using Darcy-Weisbach.
Froude Number
Compute the Froude number Fr = v/√(g·L).
Weber Number
Compute the Weber number We = (ρ·v²·L)/σ.
Wind Chill Index
Compute wind chill via the NWS formula.