Central Angle from Arc Length and Radius Calculator
Compute the central angle subtended at the centre of a circle by an arc of given arc length, using the radius: θ_radians...
Compute the central angle subtended at the centre of a circle by an arc of given arc length, using the radius: θ_radians...
Factor any positive integer into its prime components and list every divisor and the count of distinct prime factors.
Compute the secondary voltage, current, and turns ratio of an ideal transformer: V₂ = V₁ · N₂/N₁; I₂ = I₁ · N₁/N₂. Power...
Estimate a tree's age from its trunk circumference at chest height and a species-specific annual growth factor.
Find the area of any triangle from the lengths of its three sides using Heron's formula — no angles required.
Calculates approximate AQI from PM2.5 concentration and shows ratios to WHO and US EPA guidelines. Outputs a simplified...
Calculates the Wells DVT score to stratify risk: active cancer (+1), paralysis/plaster (+1), bed rest >3d (+1), along lo...
Compute the percentile rank of a chosen value within a list of numbers — the percentage of values that fall at or below...
Calculates ski slope angle (degrees), gradient (%), and vertical drop from slope length and rise, plus estimated descent...
Compute the OLS intercept of a simple linear regression y = a + b·x once the slope b has been determined: a = (Σy − b·Σx...
Approximate the definite integral ∫ from a to b of f(x) dx with a single trapezoid: (b − a)/2 × (f(a) + f(b)).
Compute the perimeter, apothem, and area of a regular polygon from its number of sides and side length.
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...