Pace, Speed & Time Converter
Convert between min/km, min/mile, km/h, and mph running paces. Predict race times and view detailed mile/kilometer split charts.
Calculations utilize Pete Riegel's endurance prediction exponent (1.06). As distance increases, a runner's threshold speed drops naturally over extended durations due to systemic glycogen depletion and cardiovascular drift.
Explore Additional Utilities
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.
Pipe thread standard — NPT ↔ BSP ↔ metric
Compare dimensions, angles, thread pitches, and sealing mechanics of NPT, BSPP, BSPT, and Metric thread systems.
Magnetic Declination
Estimate compass alignment values and offset angles between magnetic north and true north.
DPI Screen Density Sizing
Calculate typographic sizing differences across varying screen device densities and target DPI scopes.
Data Storage Units
Convert digital storage capacity sizes across bits, Bytes, MB, GB, and Terabytes.
Dye concentration — leather area ↔ product needed
Estimate leather dye volume needed based on total surface area, coat layers, and color reduction ratios.
Base64 Encoder
Encode textual strings to Base64 format, or decode Base64 back to raw text.
Angular Scales & Rotations
Convert degrees, radians, and gradians for geometric or angular rotations.
Reproductive Health Tracking Suite
Track menstrual cycles, predict ovulation day, fertile windows, and estimate pregnancy due dates & milestones.
Navy Body Fat Estimator
Estimate body fat percentage using standard US Navy circumference measurements.
Paper Size Comparer
Convert standard paper formats (A4, Letter, Legal, A3) in mm/inches and visually compare overlap.
Responsive Font Units Converter
Compute points, pixels, em, rem web font guidelines, and equivalent font sizes.
Exposure Value (EV) & Lux Converter
Convert between EV and various shutter speed, aperture, and ISO combinations, with equivalent scene lux and EV100 references.
Heat Index Feels-Like
Assess felt air heat indexes using ambient temperature and relative humidity thresholds.
Exposure Triangle & F-Stop
Calculate absolute stop adjustments, exposure reciprocal tradeoffs, f-stop quotients, and ISO noise tradeoffs.
JSON Formatter
Format, validate, beautify, and minify your JSON data structures in real-time.
Maritime & Aviation Speed
Convert maritime knots, airspeed parameters, and hourly nautical coordinates.
Packet size ↔ transmission time — network planning
Model network serialization delays and transit times across various network speeds and bandwidth options.
Braille Translator (Grade 1)
Convert standard text into visual Grade 1 Braille cell dots, and design custom cells using an interactive 6-dot braille builder.
Mechanical Power (W ↔ hp)
Convert physical engine horsepower ratings, mechanical draft forces, and electric wattages.