Gem & Jewelry Laboratory
Standardized carat measurements, karat alloy gold purity calculations, Troy ounce precious metal valuations, and historic UK assay hallmark decoding.
1. Input Weight & Unit
The modern metric carat is exactly defined as 200 milligrams. Gem weights are traditionally quoted to two decimal places (points), where 1 point equals 0.01 carats.
2. Calculated Conversions
Explore Additional Utilities
Currency Converter
Convert global currencies using simulated or fetched live rates (USD, EUR, GBP, JPY, etc.).
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Estimate photo-emulsion exposure durations for screen printing frames or solar plates using light distance calculations.
Stride length ↔ cadence ↔ running speed
Analyze running biomechanics: calculate speed based on cadence (SPM) and stride length.
Flash Guide Number Calculator
Solve the photography flash equation to find guide numbers, aperture, subject distance, or ISO speed for perfect manual flash exposures.
Stage lighting — lux ↔ foot candles ↔ beam angle
Convert between Lux and Foot-candles, and compute beam diameter coverage footprint at specific throw distances.
BBQ Smoking Wood Quantity Calculator
Calculate the optimal quantity of smoking wood chunks or chips needed based on meat weight and type.
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Convert heat transfer rates per unit area between W/m², kW/m², BTU/hr·ft², and cal/s·cm².
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Convert ship displacement tonnage to submerged volume (m³) and buoyancy force. Choose between freshwater and saltwater standards.
Reproductive Health Tracking Suite
Track menstrual cycles, predict ovulation day, fertile windows, and estimate pregnancy due dates & milestones.
Exposure Value (EV) & Lux Converter
Convert between EV and various shutter speed, aperture, and ISO combinations, with equivalent scene lux and EV100 references.
Sample size calculator — confidence level ↔ margin of error
Determine required sample sizes for research surveys or experiments based on population size, confidence levels, and target margin of error.
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.
Net metering — units exported ↔ bill credit estimate
Estimate utility bill credits, net energy offsets, and financial yields under 1:1 net metering or dual-rate net billing programs.
Electricity Billing (kWh ↔ MJ)
Analyze electric billing kilowatt-hours and physical energy auditing megajoule metrics.
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Calculate architectural light levels, illuminance indexes, and foot-candle units.
International Hat Size Matcher
Convert hat dimensions across US, UK, and European standards.
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Determine crankshaft engine RPM, radian ratios, and angular physical velocities.
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Convert concrete compressive strength between MPa, psi, and N/mm². View typical application guidelines and concrete classes.
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Match standard paper formats and fold styles to commercial envelope dimensions with proper clearance parameters.
Pipe nominal size ↔ actual OD — NPS vs DN standards
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