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
Nonagon area from apothem
regular nonagon area calculator
POST /geom/nonagon-area-apothem$0.002Developer Utilities
Nonagon perimeter calculator
P = 9 × side for a regular nonagon
POST /geom/nonagon-perimeter$0.002Developer Utilities
Oblique cone volume calculator
V = (1/3)πr²h from radius and height
POST /geom/oblique-cone$0.002Developer Utilities
Octagon apothem calculator
inradius from side length
POST /geom/octagon-apothem$0.002Developer Utilities
Octagon area calculator
regular octagon area from side length
POST /geom/octagon-area$0.002Developer Utilities
Octagon area from apothem
regular octagon area calculator
POST /geom/octagon-area-apothem$0.002Developer Utilities
Octagon circumradius calculator
regular octagon from side length, free
POST /geom/octagon-circumradius$0.002Developer Utilities
Octagonal prism calculator
volume and surface from side and height
POST /geom/octagonal-prism$0.002Developer Utilities
Octagonal pyramid calculator
volume and surface from side and height
POST /geom/octagonal-pyramid$0.002Developer Utilities
Octahedron circumradius calculator
circumscribed sphere radius from edge
POST /geom/octahedron-circumradius$0.002Developer Utilities
Octahedron inradius calculator
inscribed sphere radius from edge length
POST /geom/octahedron-inradius$0.002Developer Utilities
Octahedron surface area calculator
S = 2√3 a² from edge length
POST /geom/octahedron-surface$0.002Developer Utilities
Parabola arc length calculator
length of y=ax² over an x-range
POST /geom/parabola-arc-length$0.002Developer Utilities
Parabola from focus and directrix
equation, vertex and focal length
POST /geom/parabola-from-focus-directrix$0.002Developer Utilities
Parabola vertex form calculator
convert ax²+bx+c to a(x−h)²+k
POST /geom/parabola-vertex-form$0.002Developer Utilities
Parabolic segment area calculator
Archimedes formula from base and height
POST /geom/parabolic-segment-area$0.002Developer Utilities
Parallelogram area calculator
area from base and height
POST /geom/parallelogram-area$0.002Developer Utilities
Parallelogram area
A = a·b·sin(θ) from sides and included angle
POST /geom/parallelogram-area-angle$0.002Developer Utilities
Parallelogram height calculator
height from area and base
POST /geom/parallelogram-height$0.002Developer Utilities
Parallelogram perimeter calculator
P = 2(a + b) from adjacent sides
POST /geom/parallelogram-perimeter$0.002Developer Utilities
Pentagon area calculator
regular pentagon area from side length
POST /geom/pentagon-area$0.002Developer Utilities
Pentagon area from apothem
regular pentagon area calculator
POST /geom/pentagon-area-apothem$0.002Developer Utilities
Pentagon circumradius calculator
regular pentagon from side length, free
POST /geom/pentagon-circumradius$0.002Developer Utilities
Pentagon perimeter calculator
regular pentagon P = 5 × side
POST /geom/pentagon-perimeter$0.002Developer Utilities
Pentagonal antiprism calculator
volume and surface area from edge length
POST /geom/pentagonal-antiprism$0.002Developer Utilities
Pentagonal bipyramid calculator
volume and surface area from edge
POST /geom/pentagonal-bipyramid$0.002Developer Utilities
Pentagram area calculator
five-pointed star from circumradius
POST /geom/pentagram-area$0.002Developer Utilities
Perpendicular bisector calculator
equation from two endpoints
POST /geom/perpendicular-bisector$0.002Developer Utilities
Point in triangle checker
is a point inside a triangle?
POST /geom/point-in-triangle$0.002Developer Utilities
Point to plane distance calculator
perpendicular distance to ax+by+cz+d=0
POST /geom/point-plane-distance$0.002Developer Utilities
Point-slope form calculator
equation from a point and slope
POST /geom/point-slope-form$0.002Developer Utilities
Number of sides from interior angle calculator
regular polygon
POST /geom/polygon-sides-from-interior-angle$0.002Developer Utilities
Sum of interior angles calculator
polygon (n−2)×180°
POST /geom/polygon-sum-interior-angles$0.002Developer Utilities
Prism volume calculator
right prism volume from base area and height
POST /geom/prism-volume$0.002Developer Utilities
Prolate spheroid calculator
volume and surface from a and c
POST /geom/prolate-spheroid$0.002Developer Utilities
Pyramid lateral surface area
base perimeter and slant height
POST /geom/pyramid-lateral-area$0.002Developer Utilities
Quadrilateral area from diagonals calculator
A = ½·d1·d2·sin(θ)
POST /geom/quadrilateral-area-diagonals$0.002Developer Utilities
Quarter circle area calculator
area and arc from radius
POST /geom/quarter-circle$0.002Developer Utilities
Rectangle area calculator
A = length × width, free
POST /geom/rectangle-area$0.002Developer Utilities
Rectangle sides from area and ratio
length and width calculator
POST /geom/rectangle-from-area-ratio$0.002Developer Utilities
Rectangle perimeter calculator
P = 2(L + W) from length and width
POST /geom/rectangle-perimeter$0.002Developer Utilities
Reflect a point over the x-axis calculator
(x,y) to (x,-y)
POST /geom/reflect-point-x-axis$0.002Developer Utilities
Reflect a point over the y-axis calculator
free coordinates
POST /geom/reflect-point-y-axis$0.002Developer Utilities
Reflect a point over y=x calculator
swap coordinates
POST /geom/reflect-point-yx$0.002Developer Utilities
Regular polygon central angle calculator
360°/n from sides
POST /geom/regular-polygon-central-angle$0.002Developer Utilities
Regular polygon diagonal lengths
distinct diagonals from n and R
POST /geom/regular-polygon-diagonal$0.002Developer Utilities
Rhombic triacontahedron calculator
volume and surface from edge
POST /geom/rhombic-triacontahedron$0.002Developer Utilities
Rhombicosidodecahedron calculator
volume and surface from edge
POST /geom/rhombicosidodecahedron$0.002Developer Utilities
Rhombicuboctahedron calculator
volume and surface area from edge length
POST /geom/rhombicuboctahedron$0.002Developer Utilities
Rhombus area from diagonals calculator
A = (d1 × d2) / 2
POST /geom/rhombus-area-diagonals$0.002Developer Utilities
Rhombus perimeter calculator
perimeter from side length
POST /geom/rhombus-perimeter$0.002Developer Utilities
Rhombus side from diagonals calculator
side length from d1 and d2
POST /geom/rhombus-side-diagonals$0.002Developer Utilities
Right triangle altitude
height to hypotenuse from two legs
POST /geom/right-triangle-altitude$0.002Developer Utilities
Right triangle from two legs calculator
hypotenuse, area, angles
POST /geom/right-triangle-legs$0.002Developer Utilities
Rose curve petal counter
petals from angular coefficient k
POST /geom/rose-curve-petals$0.002Developer Utilities
Rotate a point around a center calculator
free 2D
POST /geom/rotate-point-center$0.002Developer Utilities
Rotate a point around the origin calculator
free 2D
POST /geom/rotate-point-origin$0.002Developer Utilities
Sagitta calculator
circular arc height from radius and half-angle
POST /geom/sagitta$0.002Developer Utilities
Scale a point from the origin calculator
homothety P′ = k·P
POST /geom/scale-point$0.002Developer Utilities
Circular sector centroid calculator
distance from center
POST /geom/sector-centroid$0.002