免费在线工具

Compare surface gravity on Mercury, Venus, Mars, Jupiter, the Moon, and every planet. See gravity in m/s², percent of Earth, and weight for any mass. Free, browser-based.

Assess exoplanet habitability with habitable zone, equilibrium temperature, and Earth Similarity Index (ESI). Presets for Earth, Proxima b, and Kepler-186f. Free, browser-based.

Find constellations by RA/Dec coordinates, search all 88 IAU constellations by name, or list what's visible tonight from your location. Free, browser-based.

Convert between earthquake magnitude scales — Mw, Ms, ML (Richter), mb, and Md. Estimates seismic moment, energy in joules, and TNT equivalent. Free, browser-based.

Calculate wind chill (feels-like temperature) from air temperature and wind speed. Uses the official NWS / Environment Canada 2001 formula with frostbite risk guidance. Free, browser-based.

Calculate dew point from temperature and relative humidity, or find RH from temperature and dew point. Shows vapor pressure, absolute humidity, and comfort level. Free, browser-based.

Calculate relative humidity, dew point, wet-bulb temperature, vapor pressure, absolute humidity, and mixing ratio from dry-bulb readings. Free, browser-based.

Convert between altitude and atmospheric pressure using the barometric formula or ISA standard atmosphere. Pressure in hPa, inHg, kPa, and more. Free, browser-based.

Calculate soil bulk density, moisture content, porosity, and void ratio from sample mass and volume. Supports metric (g, cm³) and imperial (lb, ft³). Free, browser-based.

Calculate rock bulk density from mass and volume, rectangular blocks, or drill cores. Porosity from grain density. Compare to typical granite, basalt, limestone, and more. Free, browser-based.

Estimate your annual carbon footprint from car travel, flights, home electricity, and natural gas. Compare to global averages with regional grid factors. Free, browser-based.

Calculate rainfall volume from catchment area and depth, estimate storm runoff with a runoff coefficient, or compute rainfall intensity (mm/hr). Metric and imperial units. Free, instant, browser-based.