VO2 Max & Aerobic Capacity Estimator
Estimate your maximal oxygen consumption (VO2 Max) using race times, Cooper 12-minute runs, or resting/max heart rate ratios.
VO2 max indicates the maximum volume of oxygen you can utilize during intense exercise. Elite cross-country skiers can score above 80 ml/kg/min, while active healthy adults range from 35 to 55 ml/kg/min.
Explore Additional Utilities
International Ring Size Matcher
Compare finger size rings across US, UK, Europe, and Asian dimensions.
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.
Ammonia toxicity — total ammonia ↔ pH ↔ toxic fraction
Calculate the highly toxic un-ionized ammonia (NH3) fraction from Total Ammonia Nitrogen (TAN), pH, and water temperature.
Stepper motor steps (degrees ↔ steps ↔ microsteps)
Convert between motor rotation angles in degrees, physical steps, and microsteps based on step angle and microstepping resolution.
Soil Permeability Converter
Convert coefficient of permeability (hydraulic conductivity) between cm/s, m/day, ft/day, and m/s with soil type drainage classifications.
Superfat percentage — excess oil ↔ skin conditioning level
Calculate excess unsaponified superfat oils and skin-conditioning moisture metrics.
Prism Power Converter
Convert ophthalmic prism power between prism diopters (PD) and degrees of deviation, with light bending estimations.
Button Size Converter
Convert button measurements between traditional ligne (L), millimeters, and fractional inches.
Watch case size — mm diameter ↔ lug width
Analyze watch case diameter proportions, lug-to-lug spans, and find the corresponding standard strap lug-width sizes.
Coal consumption — forge size ↔ hours ↔ kg of fuel
Forecast required metallurgical coal or coke fuel weight for active forge sessions.
Elastic Stretch Ratio Calculator
Calculate the stretch percentage and relaxed vs. stretched lengths of elastics or stretch fabrics.
Dog Age ↔ Human Age Equivalent
Calculate the human age equivalent of a dog based on their age and breed size category (small, medium, large, or giant), using modern veterinary curves.
Horse Height (Hands ↔ cm ↔ inches)
Convert equestrian height from traditional hands (hh, where 1 hand = 4 inches) to centimeters and inches, with pony/horse classification.
Layer height ↔ print time estimator
Estimate 3D print duration changes and total layer counts when switching layer heights and print speeds.
Heel angle ↔ righting moment
Calculate heel angle, righting arm (GZ), righting moment, and sailboat stability from displacement, vertical center of gravity, and wind force.
Scale factor (model size ↔ real world)
Convert dimensions between model design sizes and physical real-world scale targets, including imperial/metric conversions.
Troy ounce ↔ gram ↔ pennyweight
Convert weights of precious metals like gold, silver, and platinum between Troy ounces, grams, and pennyweight (dwt).
Tolerance converter (ISO fit classes ↔ clearance)
Find upper and lower deviation limits for shaft and hole ISO 286 fit classes like H7, g6, f7, and compute clearances in microns or mm.
Sail area ↔ displacement ratio
Calculate Sail Area to Displacement Ratio (SADR) to evaluate a sailboat’s performance characteristics, speed potential, and light-wind capability.
Wet folding moisture — paper weight ↔ water absorption
Calculate optimal water moisture weight to apply based on paper GSM and wood fiber absorption capacity.