Skip to main content

Ohmlark vs firenum™

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 firenum™
DetailOhmlark logo Ohmlarkfirenum™ logo firenum™
What it doesElectronics calculators for makers Free FIRE financial planner with Monte Carlo simulation and historical backtesting
StageNot given Established
FoundedNot given 2019
Based inNot given Not given
Pricing modelFreemium Free
PricingFree: $0 forever. Pro Monthly: $4 per month, cancel anytime. Pro Lifetime: $29 one-time payment. Not given
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
  • Monte Carlo simulation with up to 5,000 runs
  • Historical backtesting against every market period since 1872
  • US federal, state and payroll tax calculations for all 50 states
  • Roth conversion ladder and RMD planning
  • Six stress tests including market crash and job loss
  • Three withdrawal strategies with 59.5 rule enforcement
  • Support for 9 asset types with individual growth rates
  • Month-by-month income and expense modeling with custom timelines
  • Life event planning
  • 9-currency support with auto-detection
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
  • Runs entirely in your browser with no account needed or data stored on servers
  • Tests retirement against 154 years of historical market data since 1872
  • Calculates exact tax liability for all 50 US states plus federal and payroll taxes
  • Completely private with no data collection, selling or sharing
  • Works offline on Android with full planner functionality
Community votes00
DR (Domain Rating by Ahrefs)1 +1 (up) since last check12 no change since last check
Trust Flow (Majestic)04
Citation Flow (Majestic)034
Referring domains (Majestic)0127

4 details filled in for both companies.

More alternatives to Ohmlark More alternatives to firenum™

Help centre