Gem & Jewelry Laboratory
Standardized carat measurements, karat alloy gold purity calculations, Troy ounce precious metal valuations, and historic UK assay hallmark decoding.
1. Gold Purity Specification
2. Alloy Material & Metallurgic Spec
Explore Additional Utilities
Stride length ↔ cadence ↔ running speed
Analyze running biomechanics: calculate speed based on cadence (SPM) and stride length.
Sandpaper grit — CAMI ↔ FEPA ↔ micron rating
Convert and compare sandpaper abrasive grit sizing standards between CAMI, FEPA (P-grade), and average micron rating.
Thermal conductivity — W/m·K ↔ BTU·in/hr·ft²·°F
Translate thermal conductivity values between W/m·K, BTU·in/hr·ft²·°F, and other units.
Yeast Equivalents Calculator
Calibrate biological yeast weights and convert between fresh, active dry, and instant yeasts.
IQ score ↔ percentile rank
Map IQ scores (with standard deviations 15 or 16) to cognitive percentile ranks, rarity indices, and standard intelligence brackets.
Planck units ↔ SI units — fundamental physics constants
Translate between SI physical units and the fundamental Planck natural units based on universal constants.
Script Character ↔ Word Counter
Analyze characters, spaces, punctuation, words, and word density. Convert text density predictions between CJK and Latin scripts.
Nail size — penny (d) ↔ mm ↔ inches length
Convert traditional penny (d) nail sizes to absolute physical lengths in millimeters and inches, including standard shank gauge and nail types.
Frequency ↔ wavelength — antenna length calculation
Determine electromagnetic wavelength from frequency and velocity factors. Get recommended quarter-wave and half-wave antenna lengths.
Stage lighting — lux ↔ foot candles ↔ beam angle
Convert between Lux and Foot-candles, and compute beam diameter coverage footprint at specific throw distances.
Audio File Size & Sample Rate
Compute uncompressed audio files size based on sample rate, bit depth, and duration.
Carton CBM ↔ Container Capacity
Convert carton dimensions to Cubic Meters (CBM) and calculate carton capacity for 20ft and 40ft shipping containers.
Coffee Brewing Ratio Calculator
Determine the perfect coffee-to-water brewing ratio based on grams of coffee, milliliters of water, and cup size.
Displacement tonnage ↔ cubic meters — ship buoyancy
Convert ship displacement tonnage to submerged volume (m³) and buoyancy force. Choose between freshwater and saltwater standards.
Spring rate — lb/in ↔ N/mm — suspension setup
Convert suspension coil spring stiffness between lb/in and N/mm. Estimate coil spring rates using wire diameter, coil diameter, and active counts.
Mechanical Power (W ↔ hp)
Convert physical engine horsepower ratings, mechanical draft forces, and electric wattages.
R-value ↔ U-value — insulation thermal resistance
Convert between R-value thermal resistance and U-value heat transmittance with preset materials lookup.
Hijri ↔ Gregorian Calendar
Convert between Islamic Hijri calendar and standard Gregorian dates, with customized crescent visibility observation adjustments.
Shrink Wrap Roll Coverage
Determine how many pallets can be wrapped with a single shrink wrap roll based on roll dimensions, gauge, and layers.
Angular Motor Rotation
Determine crankshaft engine RPM, radian ratios, and angular physical velocities.