🧮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
Height from Arm Span
Estimate stature from arm span via the practical ratio rule.
Fat-Free Mass Index
Compute FFMI = lean mass (kg) / height² (m²).
Tanaka Max Heart Rate
Estimate max HR with Tanaka's formula: HRmax = 208 − 0.7 × age.
Gulati Max Heart Rate
Estimate female max HR via Gulati: HRmax = 206 − 0.88 × age.
Equivalent Radiation Dose
Compute equivalent dose H = D × WR (Sv).
Caffeine Decay
Estimate remaining caffeine after t hours assuming 5h half-life.
Blood Alcohol Decay
Estimate BAC after t hours using the linear Widmark elimination rate.
Aircraft Takeoff Speed
Estimate rotation speed VR ≈ 1.1·Vstall as a practical rule of thumb.
Stall Speed
Compute Vstall = √(2·m·g/(ρ·S·CLmax)).
Takeoff Distance Estimate
Estimate takeoff distance d ≈ V²/(2·a).
Jet Engine Thrust
Compute thrust F = ṁ·(Ve − V0).
Landing Distance Estimate
Estimate landing distance d ≈ V²/(2·a).
Aircraft Fuel Efficiency
Compute aircraft fuel efficiency = distance / fuel.
Density Altitude
Estimate density altitude DA = PA + 120·(OAT − ISA) in feet.
Parachute Terminal Velocity
Compute terminal velocity Vt = √(2·m·g/(ρ·Cd·A)).
Circular Orbit Period
Compute T = 2π·√(r³/(G·M)) for a circular orbit.
Journal Impact Factor
Compute JIF = citations / articles published in the two prior years.
Citations Per Paper
Compute average citations per paper = total citations / total papers.
Battery Life (mAh)
Estimate battery life: t (h) = capacity (mAh) / draw (mA).
Battery Charge Time (mAh)
Estimate charge time t (h) = capacity (mAh) / charger current (mA).
TMB Mifflin-St Jeor
Calcula taxa metabólica basal pela fórmula Mifflin-St Jeor (mais precisa para adultos).
BMR Katch-McArdle
Calculate your basal metabolic rate with the Katch-McArdle formula, which uses lean body mass for a sharper estimate when you know your body-fat percentage.
Proteína Diária por kg
Calcula gramas diárias de proteína com base em objetivo (sedentário 0.8, ativo 1.4, hipertrofia 2.0 g/kg).
Body Fat Calculator (US Navy)
Calculate your body fat percentage with the US Navy method, using neck, waist and hip measurements. No special scale required.
VO₂max Cooper Test
Calcula VO₂max pelo teste de Cooper (12 min corrida): (distância_m − 504.9) / 44.73.
FC Zona Karvonen
Calcula faixa-alvo de frequência cardíaca pelo método Karvonen: FC_repouso + %·(FC_máx − FC_repouso).
1RM Calculator (Brzycki)
Calculate your one-rep max (1RM) with the Brzycki formula from the weight lifted and the number of reps. Set your training loads with precision.
1RM O'Conner
Estimate your one-rep max (1RM) with the O'Conner formula from the weight lifted and reps performed. Plan training loads without attempting a true max.
Calories Burned by MET
Calculate how many calories you burn in a physical activity from its MET value, your body weight and the time spent. Compare running, lifting, cycling and more.
IMC Infantil (Z-Score aprox)
Calcula IMC e classifica pela tabela CDC aproximada (5-17 anos).
Adult Height Predictor
Estimate how tall a child will be as an adult with the mid-parental method, using the height of both parents. A simple prediction based on genetics.
FC Recuperação 1 min
Calcula recuperação cardíaca: FC_pico − FC_após_1min. Excelente >25, bom 16-25, regular ≤15.
VO₂max Rockport Walk Test
Estimate your VO₂max with the Rockport walking test (1 mile). Enter age, weight, time and heart rate to gauge your aerobic fitness.
Idade Biológica (estimativa)
Estimativa simplificada: idade cronológica ± fatores de estilo de vida (sono, exercício, fumo).
Peak Respiratory Rate Estimator
Estimate your maximum respiratory rate from your age using a common rule of thumb. Useful as a reference for training, physiology and monitoring.
Zonas de Treino (5 zonas)
Calcula 5 zonas de FC com base em FC máxima (50-60%, 60-70%, 70-80%, 80-90%, 90-100%).
Balanço Energético Diário
Calcula superávit/déficit calórico: ingestão − gasto total (TMB×fator atividade).
Déficit p/ Perda Semanal
Calcula déficit diário necessário para perder X kg/sem (1 kg gordura ≈ 7700 kcal).
Rental Income Tax (Carnê-Leão)
Calculate the tax due on rental income under the Brazilian Carnê-Leão, using the monthly progressive income tax table. Know how much to pay each month.
DARF Day Trade
Calcula DARF 20% sobre lucro líquido em day trade (descontando taxas).
Swing Trade Tax (DARF)
Calculate the tax due on swing trades via the Brazilian DARF: 15% on the monthly profit, with an exemption for sales up to R$20k. Know how much income tax to pay.
DARF Cripto
Calcula DARF cripto: isento até R$ 35 mil/mês; acima, 15% sobre ganho.
Carnê-Leão Mensal
Calcula imposto mensal pela tabela progressiva (rendimentos do exterior, autônomos).
INSS Autônomo
Calcula contribuição INSS de autônomo (11% ou 20% sobre o salário declarado, respeitando teto).
INSS Facultativo
Calcula contribuição facultativa baixa renda (5%), simplificada (11%) ou normal (20%).
Net Pro-Labore Calculator
Calculate a partner net pro-labore after deducting the 11% INSS and withholding income tax. Know how much a business owner actually takes home each month.
Dividend Yield (DY)
Calculate a stock's dividend yield (DY) by dividing the dividends paid over a year by its current price. See how much a share pays out, in seconds.
P/E Ratio (Price/Earnings)
Calculate a stock's P/E ratio by dividing its share price by earnings per share. Compare companies and gauge whether a stock looks cheap or expensive.
ROE Calculator
Calculate ROE (return on equity) by dividing net income by shareholders equity. Measures the profitability generated for shareholders.
Gross Margin
Calculate gross margin as a percentage from revenue and cost of goods sold (COGS). See how much each sale keeps before operating expenses.
Markup vs Margin
Convert markup to profit margin and back, so you stop mixing the two up. Enter a percentage and instantly see the matching selling price.
Impacto Taxa Adm. Fundos
Mostra como a taxa de administração corrói o rendimento de um fundo ao longo dos anos.
IPI Tax Calculator
Calculate the Brazilian IPI tax on a product from the tax base and rate. Instantly see the tax amount and the total price with IPI included.
Interstate ICMS Calculator
Calculate interstate ICMS tax on a sale using the 7% and 12% rates based on the origin and destination regions. Essential for issuing correct invoices in Brazil.
ITBI por Município
Calcula ITBI sobre transmissão de imóvel (alíquota típica 2% a 3%).
ITCMD por Estado
Calcula ITCMD (herança/doação) por alíquota estadual (típico 4% SP, 4-8% RJ).
Multiplicador de Receita
Multiplica os ingredientes de uma receita pelo fator desejado (linha por linha).
Tempo de Cozimento do Ovo
Indica tempo de cozimento em água fervente: mole 4 min, médio 7 min, duro 10 min.
Barbecue Meat Calculator
Calculate how much meat to buy for your barbecue from the number of adults and children. Get the right amount of meat, drinks and sides without waste.
Party Drinks Calculator
Find out how many drinks to buy for your party based on the number and profile of guests. Plan beer, soda, water and cocktails without waste.