Flash Guide Number
Solve the manual flash formula relating guide numbers, ISO, subject distance, and aperture.
Based on manual photographic flash physics formula: GN = Distance × Aperture (referenced at ISO 100).
Explore Additional Utilities
Color Code Converter
Instantly convert between HEX, RGB, HSL, and CMYK color spaces with a visual real-time preview and slider inputs.
Cooling & HVAC Power (BTU/h ↔ W)
Compare heating, cooling, and air conditioning power capacities with corresponding watt ratings.
Subtitle Timing & Readability
Evaluate subtitle card readability by computing characters per second (CPS), words per minute (WPM), and duration constraints.
Barometric Altimeter Settings
Calibrate pressure settings between QNH and QFE based on airfield elevation and temperature.
Speech Rate (WPM ↔ Pages)
Calculate presentation speech times, audio length, and page count equivalents using custom words per minute (WPM).
Radioactive Decay Half-Life
Estimate remaining isotope amounts and decay timelines from standard half-life periods.
Nautical Distance & Speed Sizer
Convert distances between nautical miles, statute miles, and kilometers, and calculate knot-based speeds.
dBm to Watts/Volts
Convert RF power levels between dBm, milliwatts, watts, and RMS voltage across 50/75 ohm impedance.
Legal Billable Hours Estimator
Convert word count of legal drafting documents to estimated billable hours based on complexity and billing rates.
Dewpoint & Relative Humidity Calculator
Calculate dewpoint, relative humidity, or air temperature using the Magnus-Tetens formula.
Fold ratio — paper thickness ↔ maximum folds possible
Compute theoretical limit of fold iterations possible for paper size and thickness (Britney Gallivan equation).
Hood size — beak width ↔ head circumference
Determine the optimal hood size, pattern dimensions, and fitting index from a bird’s beak width and cranial circumference.
Translation Pages & Pricing Converter
Convert document page count to word and character counts, and calculate translation pricing for multiple languages and target audiences.
Crown position ↔ function — hand setting vs winding
Map out the mechanical state and winding functions of crowns at positions 0, 1, and 2, including quickset dates and hacking.
Barometric Pressure Tendency Analyzer
Analyze changes in barometric pressure over time to predict short-term local weather trends.
Body Surface Area (BSA) Calculator
Calculate body surface area (BSA) for clinical dosing using Mosteller, DuBois, Haycock, and Gehan-George formulas.
VO2 Max & Aerobic Capacity Estimator
Convert running race times or heart rates into VO2 Max estimates and aerobic fitness classifications.
Power reserve — mainspring tension ↔ hours of run time
Compute total mainspring operational run time based on turns of wind, barrel capacity, and balance wheel beat rate demands.
eGFR Kidney Function Calculator
Calculate Estimated Glomerular Filtration Rate (eGFR) using the modern CKD-EPI (2021) equation to evaluate kidney stages.
Melt point — wax type ↔ degrees Celsius ↔ Fahrenheit
Analyze melt points, fragrance addition temperatures, and pour temperatures for different waxes.