Weather and Climate

  • Tornado EF Scale Calculator
    Convert a tornado's 3-second gust wind speed into its Enhanced Fujita (EF0–EF5) rating. Enter mph or km/h to instantly find the EF category.
  • Wind Chill Calculator (Celsius)
    Calculate wind chill in °C from air temperature and wind speed (km/h) using the official metric wind chill formula. Find the real "feels like" temperature.
  • Shadow Length Calculator
    Calculate the shadow length cast by any object from its height and the sun's elevation angle. Free, instant shadow length calculator using trigonometry.
  • PM10 to AQI Calculator (US EPA)
    Convert a 24-hour PM10 concentration (µg/m³) into the US EPA Air Quality Index (AQI) with category, using official EPA PM10 breakpoints.
  • R-Value & U-Value Insulation Calculator
    Calculate the R-value (thermal resistance) and U-value of insulation from material thickness and thermal conductivity. Add extra layers for total R.
  • Trip Carbon Footprint (Flight) Calculator
    Estimate the CO₂ emissions of a flight from distance, passengers and emission factor. Calculate your trip's carbon footprint in kg and tonnes instantly.
  • Thermal Conduction Heat Flow Calculator
    Calculate conductive heat flow rate and heat flux through a material using Fourier's Law: Q/t = k·A·ΔT/d. Enter conductivity, area, thickness and temperatures.
  • Coriolis Force Calculator
    Calculate the Coriolis force on a moving mass on Earth from mass, velocity and latitude using Fc = 2mvΩsin(φ), with Ω = 7.292e-5 rad/s.
  • Hurricane Category Calculator (Saffir-Simpson)
    Find the Saffir-Simpson hurricane category from sustained wind speed in mph, knots or km/h. Instantly classify Category 1-5 storms.
  • Snow Water Equivalent (SWE) Calculator
    Calculate snow water equivalent (SWE) from snow depth and density. Get SWE in cm, mm and inches of water plus the snow-to-water ratio instantly.
  • UV Index Sunburn Time Calculator
    Estimate how long until sunburn from the UV Index, your SPF sunscreen, and skin type. Quick, free sun-safety exposure-time calculator.
  • Rain Volume on Roof / Catchment Calculator
    Calculate how much rainwater your roof or catchment area collects. Enter area and rainfall depth in metric (m²/mm) or imperial (ft²/in) to get liters and gallons.
  • Cooling Degree Days (CDD) Calculator
    Calculate cooling degree days (CDD) from daily high and low temperatures and a base temperature. Estimate building cooling energy demand fast.
  • Heating Degree Days (HDD) Calculator
    Calculate Heating Degree Days (HDD) from your daily high, low and base temperature. Estimate heating demand using HDD = max(0, Tbase − mean temp).
  • Wet Bulb Globe Temperature (WBGT) Calculator
    Calculate outdoor Wet Bulb Globe Temperature (WBGT) from wet-bulb, globe, and air temperatures using WBGT = 0.7·Tw + 0.2·Tg + 0.1·Ta. Result in °C and °F.
  • Wind Pressure Calculator
    Calculate wind pressure (psf and Pa) and total force on walls, signs, and surfaces from wind speed using P = 0.00256 × v² and dynamic pressure.
  • Growing Degree Days (GDD) Calculator
    Calculate daily Growing Degree Days (GDD) from max, min, and base temperatures to track crop and pest development heat accumulation.
  • Saturation Vapor Pressure Calculator
    Calculate saturation vapor pressure from air temperature using the Tetens equation. Get results in kPa, hPa (mbar), and Pa instantly.
  • Vapor Pressure Deficit (VPD) Calculator
    Calculate Vapor Pressure Deficit (VPD) in kPa from air temperature and relative humidity. Free grow-room and greenhouse VPD tool with SVP and AVP.
  • Specific Humidity Calculator
    Calculate specific humidity from water vapor pressure and total air pressure using q = 0.622e/(p - 0.378e). Get results in g/kg and kg/kg instantly.
  • Frost Point Calculator
    Calculate the frost point temperature from air temperature and relative humidity using the Magnus formula for saturation over ice (below freezing).
  • Chill Hours Calculator
    Calculate accumulated chill hours for fruit trees using the 0–7.2°C model. See if your variety's dormancy requirement is met this winter.
  • Temperature Conversion Calculator
    Convert temperature between Celsius, Fahrenheit, Kelvin, Rankine and Reaumur. Pick any two scales, enter a value, and see the exact converted result with steps.
  • Kelvin to Fahrenheit Converter
    Convert Kelvin (K) to Fahrenheit (°F) instantly with step-by-step working. Uses °F = K × 9/5 − 459.67. Free, accurate temperature converter.

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