Developer Utilities
Small developer utilities that save a trip to a random website. Encode and decode Base64, explain a regex, build UTM links, generate QR codes and vCards, and more — the everyday helpers. Free in your browser, and available by API when you need them in a script.
Developer Utilities
Circular sector perimeter calculator
two radii plus arc
POST /geom/sector-perimeter$0.002Developer Utilities
Sector radius from area calculator
r from area and central angle
POST /geom/sector-radius-area$0.002Developer Utilities
Circular segment chord calculator
length from radius and central angle
POST /geom/segment-chord$0.002Developer Utilities
Circular segment height calculator
sagitta from radius and chord
POST /geom/segment-height$0.002Developer Utilities
Do two segments intersect?
checker and intersection point from endpoints
POST /geom/segment-intersection$0.002Developer Utilities
Segment trisection points calculator
two points that trisect a segment
POST /geom/segment-trisection$0.002Developer Utilities
Semicircle area and perimeter calculator
from radius, free
POST /geom/semicircle$0.002Developer Utilities
Slope-intercept form calculator
y=mx+b from two points, free
POST /geom/slope-intercept-form$0.002Developer Utilities
Snub cube calculator
volume and surface area from edge length
POST /geom/snub-cube$0.002Developer Utilities
Snub dodecahedron calculator
volume and surface area from edge length
POST /geom/snub-dodecahedron$0.002Developer Utilities
Sphere diameter from volume calculator
derive diameter from V
POST /geom/sphere-diameter-volume$0.002Developer Utilities
Sphere great circle calculator
circumference and area from radius
POST /geom/sphere-great-circle$0.002Developer Utilities
Sphere radius from surface area calculator
r = √(S / 4π)
POST /geom/sphere-radius-surface$0.002Developer Utilities
Sphere surface area calculator
S = 4πr² from radius free
POST /geom/sphere-surface$0.002Developer Utilities
Spherical cap surface area
A = 2πRh from radius and height
POST /geom/spherical-cap-surface$0.002Developer Utilities
Spherical lune area calculator
radius and dihedral angle to surface area
POST /geom/spherical-lune$0.002Developer Utilities
Spherical wedge volume calculator
radius and dihedral angle to volume
POST /geom/spherical-wedge$0.002Developer Utilities
Spindle torus calculator
self-intersecting volume and area
POST /geom/spindle-torus$0.002Developer Utilities
Square area calculator
A = side × side, free
POST /geom/square-area$0.002Developer Utilities
Square diagonal calculator
diagonal length from side (s√2)
POST /geom/square-diagonal$0.002Developer Utilities
Square side from area calculator
side = √A, free
POST /geom/square-side-area$0.002Developer Utilities
Square side from diagonal calculator
side = d/√2, free
POST /geom/square-side-diagonal$0.002Developer Utilities
Stellated octahedron calculator
volume and surface area from edge length
POST /geom/stellated-octahedron$0.002Developer Utilities
Stewart's theorem calculator
cevian length from sides and base division
POST /geom/stewart-theorem$0.002Developer Utilities
Superellipse area calculator
Lamé curve area from semi-axes and exponent
POST /geom/superellipse-area$0.002Developer Utilities
Tangent length from external point
√(d²−r²) calculator
POST /geom/tangent-length-point$0.002Developer Utilities
Tetrahedron height calculator
vertical height from edge length
POST /geom/tetrahedron-height$0.002Developer Utilities
Tetrahedron inradius calculator
inscribed sphere radius from edge length
POST /geom/tetrahedron-inradius$0.002Developer Utilities
Tetrahedron midradius calculator
midsphere radius from edge length
POST /geom/tetrahedron-midradius$0.002Developer Utilities
Tetrahedron surface area calculator
A = a²√3 from edge length
POST /geom/tetrahedron-surface$0.002Developer Utilities
Trapezoid diagonal calculator
both diagonals from sides and height
POST /geom/trapezoid-diagonal$0.002Developer Utilities
Trapezoid height from area calculator
bases and area to height
POST /geom/trapezoid-height$0.002Developer Utilities
Trapezoid perimeter calculator
sum of four side lengths
POST /geom/trapezoid-perimeter$0.002Developer Utilities
Triakis tetrahedron calculator
volume and surface area from edge length
POST /geom/triakis-tetrahedron$0.002Developer Utilities
Triangle altitude lengths calculator
heights from three sides
POST /geom/triangle-altitudes$0.002Developer Utilities
Triangle angle bisector lengths
three sides to all three lengths
POST /geom/triangle-angle-bisectors$0.002Developer Utilities
Triangle inequality checker
do three side lengths form a valid triangle?
POST /geom/triangle-inequality$0.002Developer Utilities
Triangle inradius calculator
inscribed circle radius from three sides
POST /geom/triangle-inradius$0.002Developer Utilities
Triangle semiperimeter calculator
s = (a+b+c)/2 from three sides
POST /geom/triangle-semiperimeter$0.002Developer Utilities
Triangle type by angles
acute, right or obtuse classifier
POST /geom/triangle-type-angles$0.002Developer Utilities
Triangular pyramid calculator
volume and surface from edge & height
POST /geom/triangular-pyramid$0.002Developer Utilities
Truncated cube calculator
volume and surface area from edge length
POST /geom/truncated-cube$0.002Developer Utilities
Truncated dodecahedron calculator
volume and surface from edge length
POST /geom/truncated-dodecahedron$0.002Developer Utilities
Truncated icosidodecahedron
volume and surface from edge length
POST /geom/truncated-icosidodecahedron$0.002Developer Utilities
Truncated octahedron calculator
volume and surface area from edge length
POST /geom/truncated-octahedron$0.002Developer Utilities
Truncated tetrahedron calculator
volume and surface area from edge length
POST /geom/truncated-tetrahedron$0.002Developer Utilities
Direction angle of a vector calculator
2D atan2 from components
POST /geom/vector-angle-2d$0.002Developer Utilities
Adjusted body weight calculator
ABW from actual & ideal weight, free
POST /health/adjusted-body-weight$0.002Developer Utilities
Appendicular skeletal muscle mass calculator
ASM & ASMI
POST /health/appendicular-muscle-mass$0.002Developer Utilities
Original Harris-Benedict 1919 BMR calculator
classic basal metabolic rate
POST /health/bmr-harris-benedict-1919$0.002Developer Utilities
Mueller equation BMR calculator
basal rate from weight, height, age
POST /health/bmr-mueller$0.002Developer Utilities
Oxford Henry BMR calculator
basal rate from weight, sex, age
POST /health/bmr-oxford-henry$0.002Developer Utilities
Schofield BMR calculator
WHO basal metabolic rate by weight, sex, age
POST /health/bmr-schofield$0.002Developer Utilities
Body Roundness Index calculator
BRI from waist and height, free
POST /health/body-roundness-index$0.002Developer Utilities
Covert Bailey body fat calculator
four girth measurements, free
POST /health/bodyfat-covert-bailey$0.002Developer Utilities
Deurenberg body fat from BMI
age and sex equation, free
POST /health/bodyfat-deurenberg$0.002Developer Utilities
Gallagher body fat calculator
BMI, age & sex equation, free
POST /health/bodyfat-gallagher$0.002Developer Utilities
Jackson-Pollock 3-site body fat for women
skinfolds + age, free
POST /health/bodyfat-jp3-women$0.002Developer Utilities
Jackson-Pollock 4-site body fat calculator
skinfold sum & age, free
POST /health/bodyfat-jp4$0.002Developer Utilities
Parrillo 9-site body fat calculator
skinfold sum formula
POST /health/bodyfat-parrillo$0.002