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Ohmlark vs BuildWire Calc

A side-by-side comparison built from both listings. Blank cells mean the company has not given that detail; we never guess.

Ohmlark compared with BuildWire Calc
DetailOhmlark logo OhmlarkBuildWire Calc logo BuildWire Calc
What it doesElectronics calculators for makers Offline calculators for electricians, builders and HVAC technicians
StageNot given Not given
FoundedNot given Not given
Based inNot given US
Pricing modelFreemium Freemium
PricingFree: $0 forever. Pro Monthly: $4 per month, cancel anytime. Pro Lifetime: $29 one-time payment. Free: nine calculators (voltage drop, Ohm's law, watts to amps, concrete slab, roof pitch, board feet, BTU, CFM, BTU to kW), no time limit. Pro: $9.99 per year or $19.99 lifetime (one payment, no renewal).
Key features
  • Resistor Color Code: read 4, 5 and 6-band resistors or find bands for a value
  • LED Resistor: pick the current-limiting resistor and power rating
  • Voltage Divider: output voltage, loading effect, or solve R2 for target Vout
  • RC Filter: cutoff frequency, time constant and attenuation at any frequency
  • LC Resonance: resonant frequency, characteristic impedance and Q
  • 555 Timer: astable frequency/duty cycle and monostable pulse width
  • Battery Life: runtime from capacity, active/sleep current and duty cycle
  • PCB Trace Width: IPC-2221 trace width for current and temperature rise
  • Electronics Unit Converter: SI prefixes, AWG to mm², mil to mm, dBm to mW, oz copper
  • Wire sizing and voltage drop calculations
  • Conduit fill and box fill calculations
  • Offline operation with no network required
  • Transparent calculation steps and NEC warnings
  • Job organization and PDF/CSV export
  • Motor and generator sizing calculators
  • Power and conversion calculators
  • Building calculations for concrete and roof pitch
  • No ads and no account required
  • Private with data staying on device
What makes it different
  • Real E-series resistor values, not ideal numbers
  • Engineering notation input and result sharing as links
  • No ads, no tracking, no sign-up for free calculators
  • Whole-device BOM costing and battery-life summary in Pro
  • Works on phone at the bench
  • Works completely offline with no network or cellular signal required
  • Private by design with no account, no ads, and calculations never leaving your device
  • Shows exact NEC formulas and calculation steps so you can verify results before fieldwork
  • Over 35 specialized calculators covering electrical, building and HVAC trades
  • Tested code with automated tests against independently worked examples
Community votes00
DR (Domain Rating by Ahrefs)1 +1 (up) since last checkNot checked yet no change since last check
Trust Flow (Majestic)00
Citation Flow (Majestic)013
Referring domains (Majestic)01

5 details filled in for both companies.

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