Growing Degree Days (GDD)
Compute the growing degree days (GDD), GDD = (Tmax + Tmin)/2 − Tbase, the daily thermal accumulation above the base temperature below which the plant does not grow. Since crop development is driven by temperature, summing degree days predicts phenological stages — flowering, maturity, harvest — more accurately than the calendar. Also used for pests and insects. Enter the day's maximum and minimum temperatures and the crop base temperature.
Result
—
Growing degree days (GDD)
Plants do not count days on the calendar — they count heat. Below a base temperature (Tbase) specific to each species, development practically comes to a halt. Growing degree days accumulate the useful heat of each day: GDD = (Tmax + Tmin)/2 − Tbase. Adding up the degree days since sowing predicts, with far greater accuracy than the calendar offers, when flowering, grain fill and harvest will arrive — a hot summer speeds everything up, and a cool one holds it back. The same method predicts pest emergence and the number of insect generations over a growing season. Enter the maximum and minimum temperatures of the day and the base temperature.
Related Tools
Martensite Start Temperature Ms (Andrews)
Computes the Ms temperature, the point at which austenite starts transforming into martensite during quenching, using the linear Andrews equation: Ms(°C) = 539 − 423·C − 30.4·Mn − 17.7·Ni − 12.1·Cr − 7.5·Mo, with every content in mass percent. Nearly every element dissolved in austenite lowers Ms — cobalt and aluminium are the exceptions and raise it —, but carbon dominates by far: each 0.1 % of carbon drops Ms by 42 °C, nearly 14 times the effect of the same manganese content. Knowing Ms sets the martempering bath temperature, tells whether retained austenite will survive at room temperature, and predicts how severe the quenching stresses will be, because a low Ms makes the martensite expansion happen late, with the part already cold and rigid, and that is where cracks appear. The correlation is fitted to low-alloy steels with carbon up to roughly 0.6 %, and the page rejects compositions above 0.8 % carbon, where the extrapolation loses its footing. Enter the carbon, manganese, nickel, chromium and molybdenum contents.
Temperature-Humidity Index (THI) for Cattle
Calculates the temperature-humidity index (THI) used to gauge heat stress in cattle, in the metric form of the 1971 NRC formula, from air temperature and relative humidity. Below 72 the animal is comfortable; 72 to 78 is alert, 79 to 88 is danger and above 88 is emergency. Enter temperature and relative humidity.
Junction Temperature
Calculate the junction temperature of a power semiconductor, T_j = T_a + P × R_th, from the ambient temperature T_a, the dissipated power P and the total junction-to-ambient thermal resistance R_th (°C/W). The result, in °C, is the device's internal temperature (silicon junction), which must not exceed the manufacturer's limit (typically 150 °C) on pain of failure. The thermal resistance adds the junction-to-case, case-to-heatsink and heatsink-to-ambient stages. Lowering R_th (larger heatsink, ventilation, thermal paste) lowers the junction temperature. It is the central calculation of power electronics thermal design. Enter the ambient temperature, the dissipated power and the thermal resistance.
Brake Temperature Rise
Estimate a brake's temperature rise from one braking, ΔT = E ÷ (m·c), from the braking dissipated energy E (J), the mass of the heat-absorbing component m (kg, the disc or drum) and the material specific heat c (J/(kg·°C), ~460 for steel, ~900 for aluminum). When a brake dissipates a braking's kinetic energy (converting it to heat), this heat is initially ABSORBED by the disc or drum mass, raising its temperature. This formula estimates that rise assuming ALL the heat goes into the component mass, with no loss to the environment (a conservative assumption, valid for a quick, isolated braking — in prolonged braking, part of the heat is dissipated by convection and radiation simultaneously). The temperature rise is critical because friction materials have a thermal limit: above a certain temperature (300-500°C for organic materials, more for metallic/ceramic), friction drops sharply (the FADING phenomenon, which has caused many mountain-descent accidents), the material degrades, and the disc can warp or crack from thermal shock. So severe-duty brakes use large discs (more mass, more heat-absorbing capacity), vented (more dissipation) and high-melting-point materials. This calculation is the heart of brake THERMAL design. Enter the dissipated energy, the mass and the specific heat.
Sous-vide Time by Temperature and Thickness
Computes sous-vide cooking time in minutes from meat thickness in centimeters and water bath temperature in Celsius.
Flood Rainfall Accumulation Calculator (mm)
Estimates flood duration from accumulated rainfall in millimeters over a few days and the basin drainage capacity.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.