φ (Phi) Coefficient from a 2×2 Contingency Table Calculator
Compute the φ (phi) coefficient — the Pearson correlation between two binary variables — from a 2 × 2 contingency table...
Compute the φ (phi) coefficient — the Pearson correlation between two binary variables — from a 2 × 2 contingency table...
Compute the mechanical work done by a constant force over a displacement, including the cosine factor for off-axis force...
Counts the number of trailing zeros in n factorial using the standard Legendre formula based on factors of 5.
Compute the 2-class softmax probabilities (positive vs negative) from raw logits z₁ and z₂: p_i = exp(z_i) / [exp(z₁) +...
Estimates the maximum mortgage loan a household can afford from their maximum monthly payment, interest rate, and loan t...
Compute the mean and variance of a Pareto(x_m, α) distribution. The mean is finite only for α > 1, the variance only for...
Calculates the Carnot COP for a heat pump COP_HP = T_H/(T_H−T_C) and for a refrigerator COP_R = T_C/(T_H−T_C). Also show...
Estimate how long a download will take given a file size in MB or GB and an internet connection speed in Mbps.
Estimate how long a battery will last from its capacity (mAh or Ah) and the load current draw, with a configurable real-...
Compute the Pearson correlation coefficient (r), r², and the slope/intercept of the best-fit line for two equal-length l...
Compute the arc length of a circle from the radius and the central angle in degrees.
Compute the percentage change from an original value to a new value — positive for an increase, negative for a decrease.
Standard deviation is "average distance from the average". That one sentence covers 90% of everything you ever need to remember about it.
Every "X% of Y" problem, every "what percent of", every percent-change question — written out the way you'd actually say them.
These calculators were technically reviewed by Daniel Oh for accuracy.
Calculate an age-based pediatric dose from a known adult dose using Young’s Rule. A quick educational tool for students...