Free Online Tools

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.

Calculate air density from temperature, pressure, and humidity, or from altitude. Shows kg/m³, virtual temperature, speed of sound, and comparison to sea-level standard. 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.

Calculate volumetric flow rate Q = A × v for pipes and open channels, estimate flow with Manning's equation, or convert between L/s, GPM, CFS, and m³/s. Metric and imperial units. Free, instant, browser-based.

Calculate river discharge Q from channel width, depth, and mean velocity (velocity–area method), trapezoidal cross-sections with bank slope, or Manning's equation. Results in m³/s, L/s, and CFS with river size classification. Free, browser-based.

Analyze temperature and precipitation climate data. Paste daily or monthly values to get mean, min, max, std dev, heating/cooling degree days, wet days, dry spells, and Northern Hemisphere seasonal summaries (DJF, MAM, JJA, SON). Free, browser-based.

Calculate ultimate and allowable soil bearing capacity using Terzaghi's equation for strip, square, and circular footings. Enter cohesion, friction angle φ, unit weight, depth, and footing width. Compare applied pressure to q_allow. Metric and imperial units. Free, browser-based.