Optics & Vision Lab
Analyze lens focal lengths, convert clinical visual acuity fractions, compute prism deviations, simulate color temperatures, and evaluate light bulb efficacy.
Luminous Efficacy Calculator
Calculate efficacy in lumens per watt, evaluate electrical efficiency relative to theoretical maximums, and compare light bulb technologies.
13.78% of maximum physics limit (683 lm/W)
High Efficiency (Standard LED)
Outstanding modern standard. Consumes 85% less power than equivalent incandescent bulbs.
Explore Additional Utilities
dBm to Watts/Volts
Convert RF power levels between dBm, milliwatts, watts, and RMS voltage across 50/75 ohm impedance.
Oxygen Saturation & PaO2 Converter
Convert blood oxygen saturation (SpO2) to partial pressure of oxygen (PaO2) using the clinical Severinghaus-Ellis model.
Base64 ↔ hex ↔ binary — encoding format converter
Convert raw text strings or bytes bidirectionally between Base64, Hexadecimal, Binary, and standard ASCII formats.
Rock density ↔ tonnage — volume to weight for blasting
Determine solid rock and broken loose rock tonnage from volume based on rock type densities, useful for blasting and haulage design.
Essential oil dilution — drops ↔ % in carrier oil
Convert dilution percentages to drop counts and precise weights for facial, body, and therapeutic carrier oils.
Chart Scale Converter
Convert map dimensions in millimeters to real-world marine navigation distances or vice versa based on nautical chart scale.
Firewood volume — cords ↔ cubic meters ↔ cubic feet
Convert between cords, face cords, steres, and cubic volumes. Compute solid wood volumes, green or dry weight, and thermal BTU outputs.
ND Filter Stops Converter
Convert ND filter labels (ND density, optical density, and stop reduction) and calculate long exposure shutter speed compensation.
Clinical Blood Pressure Gauges
Compare clinical medical blood pressure or vacuum values between mmHg and kPa units.
Color Code Converter
Instantly convert between HEX, RGB, HSL, and CMYK color spaces with a visual real-time preview and slider inputs.
Certificate validity — days ↔ expiry date calculation
Convert between certificate lifetime in days, months, or years, and calculate exact UTC expiration times with leap year support.
Subtitle Timing & Readability
Evaluate subtitle card readability by computing characters per second (CPS), words per minute (WPM), and duration constraints.
Halftone frequency — lpi ↔ dpi requirement
Calculate the necessary image resolution (DPI/PPI) for halftone printing line screens (LPI) and analyze grayscales.
Heat flux — watts per square meter ↔ BTU/hr·ft²
Convert heat transfer rates per unit area between W/m², kW/m², BTU/hr·ft², and cal/s·cm².
Aviation Fuel Weight Calculator
Calculate volume-to-weight changes for standard aviation fuels (Jet A-1, Avgas) across metric and imperial systems.
Grout coverage — tile size ↔ joint width → bags needed
Estimate dry grout requirements based on tile dimensions, joint width, joint depth, and overall surface area.
Coordinates to UTM/MGRS
Convert standard Latitude & Longitude decimal coordinates to UTM and military grid reference (MGRS) systems.
CFM ↔ m³/hour — air flow for ventilation
Convert ventilation air flow rates and reference standard design volumes for common room types and equipment hoods.
Morse code ↔ NATO phonetic — dual encoding
Convert raw text into international Morse Code (DITs and DAHs) and official NATO spelling phonetics synchronously.
Optical density ↔ transmittance — filter blocking level
Convert between Optical Density (OD), transmittance fraction/percentage, and attenuation factors for safety glasses.