Math & Numbers
Convert luminance between cd/m² (nit, SI base), stilb (1 = 10000 cd/m²), cd/ft² (1 = 10.76391 cd/m²), foot-lambert (1 = 3.426263 cd/m²), apostilb (1 = 0.31831 cd/m²), lambert (1 = 3183.099 cd/m²), and millilambert (1 = 3.183099 cd/m²). All non-SI units except stilb carry a 1/π factor from Lambertian diffuse-emission assumptions. Reference values: LCD display ≈ 200–300, comfortable eye level ≈ 1000, sun surface ≈ 1.6×10⁹ cd/m².
luminance-converterMath & Numbers
Convert luminous intensity between candela (cd, SI base, = 1/683 W/sr at 540 THz), millicandela (1 = 0.001 cd), and candlepower (1 = 0.981 cd, obsolete standard candle). Converts via candela to the target unit and lists the equivalent value in all three units for reference. Reference values: indicator LED ≈ 5–20 mcd, flashlight ≈ 100–1000 cd, car headlight high beam ≈ 75000 cd.
luminous-intensity-converterMath & Numbers
Fit a binary logistic regression model with gradient descent and predict class probabilities
logistic-regression-calculatorMath & Numbers
Compare two independent samples with the nonparametric Mann-Whitney U rank-sum test
mann-whitney-u-test-calculatorMath & Numbers
Calculate the margin of error for a mean or proportion from sample size, confidence level, and variability
margin-of-error-calculatorMath & Numbers
Calculate logarithms with any valid base, with optional log10, log2, and natural-log comparisons
logarithm-calculatorMath & Numbers
Calculate profit margin, markup, and selling price based on cost and desired margin percentage
margin-calculatorFinance
Calculate loan payments, interest, and amortization schedule for various loan types
loan-calculatorCalculator
Calculate winning probabilities for various lottery games
lottery-probabilityMath & Numbers
Convert liters to US cups with configurable decimal precision
liter-to-cupMath & Numbers
Convert liters to US liquid pints with configurable decimal precision
liter-to-pintMath & Numbers
Convert liters to US liquid quarts with configurable decimal precision
liter-to-quart