Ventilation air changes and dilution time calculator
Trace source-free well-mixed concentration decay from room volume, clean-air-equivalent flow and a fixed background concentration.
Open calculatorScience & engineering
Practical physics and chemistry with units and assumptions in view.
Showing 73–96 of 165 tools
Fan and system curve operating point calculator
Intersect an assumed quadratic fan curve with static-plus-quadratic system resistance, including a speed-ratio scenario and input-power estimate.
Open calculatorCompressed air receiver drawdown calculator
Estimate isothermal free-air storage and pressure-band drawdown duration with concurrent compressor supply and a consistent reference state.
Open calculatorFalling head tank drain time calculator
Integrate ideal small-orifice outflow as the water head falls in a vented constant-area tank, showing a changing level curve.
Open calculatorCooling coil condensate and air load calculator
Compare entered inlet and outlet air states to estimate water removal and moist-air enthalpy reduction at a supplied dry-air mass flow.
Open calculatorSoil core moisture and porosity calculator
Reconcile wet and dry core masses with tare, core volume and particle density to calculate dry-basis moisture, volumetric water and pore saturation.
Open calculatorGrowing degree days temperature log calculator
Accumulate Celsius heat units from entered daily minima and maxima using either an uncapped daily mean or explicit lower and upper modified bounds.
Open calculatorIrrigation salinity leaching requirement calculator
Inspect the conventional EC-based steady leaching fraction and distinguish root-zone drainage water from delivery-efficiency losses.
Open calculatorPump available NPSH calculator
Calculate available suction head from absolute reservoir and vapor pressures, liquid density, elevation and entered suction loss, preserving signed margin comparisons.
Open calculatorTruck axle load position calculator
Calculate static two-axle reaction changes from cargo mass and position, with signed headroom against user-entered limits.
Open calculatorFleet EV charging window calculator
Simulate a slot-based earliest-deadline charging schedule under plug, vehicle power and site power limits, reporting unmet battery energy.
Open calculatorStrong acid base titration curve calculator
Plot ideal strong monoprotic acid and strong base titrations with water autoionization, equivalence volume and selected-addition pH.
Open calculatorBicycle climbing power and grade calculator
Estimate steady bicycle climbing power from rise/run grade, total mass, rolling resistance, air drag, wind and drivetrain efficiency.
Open calculatorPulley RPM ratio and shaft power calculator
Calculate driven RPM, belt pitch-line speed and output torque from pitch diameters, entered slip and overall power efficiency.
Open calculatorPipe insulation steady heat loss calculator
Estimate cylindrical insulation conduction and external film heat loss, surface temperature and a same-film bare-pipe comparison.
Open calculatorFertilizer NPK blend nutrient balance calculator
Add nutrient contributions from fertilizer labels and compare the entered blend with user-supplied N, phosphate-equivalent and potash-equivalent targets.
Open calculatorThree phase star delta balanced load calculator
Calculate line and phase quantities for an ideal balanced sinusoidal star or delta load from per-phase impedance and power factor.
Open calculatorInverter running load and startup surge budget calculator
Budget running watts, conservative apparent power and an entered startup scenario with separate W and VA limits instead of a single wattage shortcut.
Open calculatorSolar string cold Voc voltage ceiling calculator
Estimate linear cold-corrected module and string open-circuit voltage against an entered DC ceiling and optional headroom allowance.
Open calculatorTransformer impedance voltage regulation calculator
Estimate first-order transformer regulation and copper loss from percent resistance and reactance on one rating base, load fraction and leading or lagging PF.
Open calculatorGear ratio engine RPM and road speed calculator
Calculate theoretical road speed from engine RPM, transmission ratio, final drive and tire diameter, with a four-point RPM comparison.
Open calculatorEngine displacement bore stroke and overbore calculator
Calculate engine swept displacement and the geometric effect of an entered overbore using millimetres, cubic centimetres and litres.
Open calculatorStatic engine compression ratio calculator
Calculate static compression ratio from cylinder geometry, measured chamber, compressed gasket, deck height and signed piston volume.
Open calculatorRainwater daily tank balance calculator
Simulate daily harvest, overflow, delivery and unmet demand across candidate tank sizes using an explicit harvest-before-demand timing convention.
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