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
BJT Voltage Divider Bias Calculator
POST /elec/bjt-divider-bias$0.002Developer Utilities
Full-wave rectifier output calculator
DC average and peak voltage
POST /elec/fullwave-rectifier$0.002Developer Utilities
Impedance from R and X calculator
|Z| and phase free
POST /elec/impedance-from-rx$0.002Developer Utilities
LED series string calculator
max LEDs and dropping resistor
POST /elec/led-series-string$0.002Developer Utilities
Linear regulator power calculator
dissipation for heat sink sizing
POST /elec/linear-regulator-power$0.002Developer Utilities
Zener diode power calculator
check dissipation and rating
POST /elec/zener-power$0.002Developer Utilities
Aliasing frequency calculator
fold signal above Nyquist to f_alias
POST /elec/aliased-frequency$0.002Developer Utilities
Battery C rate calculator
convert C rate and current
POST /elec/battery-c-rate$0.002Developer Utilities
Battery depth of discharge calculator
usable capacity and cycle life
POST /elec/battery-dod$0.002Developer Utilities
Binary multiplication calculator
shift and add steps
POST /elec/binary-multiplication$0.002Developer Utilities
Binary to BCD converter
binary number to 8421 BCD (7-segment)
POST /elec/binary-to-bcd$0.002Developer Utilities
Bits Needed for Values Calculator
Minimum Binary Width
POST /elec/bits-for-values$0.002Developer Utilities
Bitwise XOR calculator
exclusive OR of two integers, free
POST /elec/bitwise-xor$0.002Developer Utilities
Boolean expression truth table calculator
AND, OR, NOT
POST /elec/boolean-truth-table$0.002Developer Utilities
Boost converter duty cycle calculator
D = 1 − Vin/Vout, free
POST /elec/boost-duty$0.002Developer Utilities
Switching converter input current calculator
Iin from Pout, Vin and η
POST /elec/converter-input-current$0.002Developer Utilities
DAC output voltage calculator
Vout from code, Vref and bits
POST /elec/dac-output$0.002Developer Utilities
dB to gain ratio calculator
convert voltage or power gain
POST /elec/gain-db-to-ratio$0.002Developer Utilities
Gray code to binary calculator for encoder values
POST /elec/gray-to-binary$0.002Developer Utilities
Johnson counter states calculator
twisted-ring states (2n)
POST /elec/johnson-counter$0.002Developer Utilities
Monostable timer period calculator
calculate one-shot duration
POST /elec/monostable-period$0.002Developer Utilities
MOSFET switching loss calculator
Psw from Vds, Id, tr, tf, f
POST /elec/mosfet-switching-loss$0.002Developer Utilities
555 astable frequency calculator
calculate frequency from R1, R2 and C
POST /elec/ne555-frequency$0.002Developer Utilities
Op-amp buffer follower calculator
unity gain and output voltage
POST /elec/opamp-follower$0.002Developer Utilities
Op-amp full-power bandwidth calculator
f = SR/(2π·Vpeak), free
POST /elec/opamp-full-power-bw$0.002Developer Utilities
Op-amp integrator calculator
output slope and RC time constant
POST /elec/opamp-integrator$0.002Developer Utilities
Product of sums maxterm calculator
canonical POS expression
POST /elec/pos-maxterms$0.002Developer Utilities
PWM resolution bits calculator
timer clock and PWM frequency
POST /elec/pwm-resolution$0.002Developer Utilities
Signed magnitude representation calculator
encode and decode binary
POST /elec/signed-magnitude$0.002Developer Utilities
Transistor power dissipation calculator
P = Vce × Ic free
POST /elec/transistor-power$0.002Developer Utilities
UART frame time calculator
baud rate, data, parity and stop bits
POST /elec/uart-frame-time$0.002Developer Utilities
XOR checksum calculator
byte list integrity check
POST /elec/xor-checksum$0.002Developer Utilities
Solar battery bank sizing calculator
Ah from load, autonomy & DoD
POST /elec/solar-battery-bank$0.002Developer Utilities
Wire gauge selection calculator
current, length and voltage drop
POST /elec/wire-gauge-selection$0.002Developer Utilities
Fuse I²t melting calculator
compare fault current and duration
POST /elec/fuse-i2t$0.002Developer Utilities
Thermal resistance stack calculator
junction temperature rise
POST /elec/thermal-resistance-stack$0.002Developer Utilities
Wire ampacity derating calculator
temperature and bundling factors
POST /elec/wire-ampacity-derating$0.002Developer Utilities
dB attenuation calculator
voltage & power linear ratios
POST /elec/db-attenuation$0.002Developer Utilities
Power bank phone charges calculator
recharges from mAh and efficiency
POST /elec/power-bank-charges$0.002Developer Utilities
SWR from reflection coefficient calculator
VSWR and return loss free
POST /elec/swr-from-reflection$0.002Developer Utilities
Haversine great-circle distance
km, mi, m between two points
POST /geo/haversine-distance$0.002Developer Utilities
Central angle between two latitude longitude points
POST /geo/central-angle$0.002Developer Utilities
Nearest point on polyline
closest lat/lon on a route, free
POST /geo/nearest-point-on-polyline$0.002Developer Utilities
Point to infinite great-circle line distance calculator
POST /geo/point-to-line-distance$0.002Developer Utilities
Bearing to 32-point compass box
degrees to NbE, NNE, NEbN… free
POST /geo/bearing-to-cardinal32$0.002Developer Utilities
Final bearing at destination
great-circle arrival azimuth calculator
POST /geo/final-bearing$0.002Developer Utilities
Grid bearing from true
meridian convergence converter, free
POST /geo/grid-bearing$0.002Developer Utilities
Polar coordinate plane distance
law of cosines calculator
POST /geo/polar-distance$0.002Developer Utilities
Relative bearing from heading
vessel target angle calculator
POST /geo/relative-bearing$0.002Developer Utilities
Cube surface area calculator
6·a² from the edge length
POST /math/cube-surface-area$0.002Developer Utilities
Quadrant bearing to azimuth converter
POST /geo/quadrant-to-azimuth$0.002Developer Utilities
Cube volume, surface area and space diagonal from edge length
POST /math/cube-v-a-d$0.002Developer Utilities
Densify a geodesic line with evenly spaced latitude/longitude vertices
POST /geo/densify-line$0.002Developer Utilities
Minimum bounding rectangle calculator for 2D points
POST /geo/min-bounding-rectangle$0.002Developer Utilities
Convex hull of points
monotone chain scan, free
POST /geo/polygon-convex-hull$0.002Developer Utilities
Polygon edge bearings
calculate azimuth for every segment
POST /geo/polygon-edge-bearings$0.002Developer Utilities
Polygon convexity test
check if a simple polygon is convex
POST /geo/polygon-is-convex$0.002Developer Utilities
Spherical excess polygon area
Girard km² from lat/lon, free
POST /geo/spherical-polygon-area$0.002Developer Utilities
Cube volume calculator
a³ from the side length
POST /math/cube-volume$0.002Developer Utilities
Cubic feet of a cylinder
volume from radius and height in feet
POST /math/cubic-feet-cylinder$0.002