All Engineering Calculators
39 free tools for HVAC design, building-code compliance and everyday engineering math.
You have no favorites starred. Uncheck the filter, or star a calculator to add it.
Airflow
-
ACH to CFM
Convert between airflow and air changes per hour for a room, in US or SI units.
-
Infiltration & Pressure
Crack-method infiltration through windows and doors, plus the building pressure from…
NEW
-
Air Mixing
Calculate the mixed air temperature of two or three airstreams, in US or metric…
-
Diffuser Sizer
Find the supply diffuser or return grille sizes for an airflow at a chosen neck…
-
Ductulator
Ductulator / Duct Size Calculator. Users can size Flex, Ductboard, Metal, or Fabric…
-
Temp Loss in Duct
Finding the heat loss through an insulated air duct.
-
FPM to CFM
Calculate the face velocity or the airflow for an air diffuser, in US or metric…
-
Transfer Duct
Size return air transfer ducts and pass-through grilles: minimum grille free area…
-
Ventilation Rates
Look up outdoor air and exhaust rates from ASHRAE 62.1, 62.2 and 170, the IMC and…
NEW
Building Code
-
CLTD Roof, Wall & Hourly
Find ASHRAE CLTD roof and wall numbers, the hourly CLTD corrected for your design…
-
U-Factor/SHGC
Look up the default window, skylight and door U-factor, SHGC and VT from the 2024…
-
SH Window Sizer
Converts single hung window size codes, such as SH 24 or SH H32, to the frame size…
-
Ventilation Rates
Look up outdoor air and exhaust rates from ASHRAE 62.1, 62.2 and 170, the IMC and…
Equipment
-
Coil Calculator
Calculate total, sensible and latent coil capacity, entering and leaving air…
-
Condensate Pump
Size a condensate pump: calculate or enter the coil condensate, then list the pumps…
NEW
-
Condensate Converter
Convert condensate and moisture between latent Btu/h, kW, pints per day, gallons per…
-
Cooling Load Est.
Estimate cooling tons, lighting and electrical load, and occupants from floor area…
-
Infiltration & Pressure
Crack-method infiltration through windows and doors, plus the building pressure from…
NEW
-
Dehumidifier Sizer
Size a dehumidifier from the latent load in pints/day, Btu/h or kW, and list the…
-
EER SEER SEER2…
Convert between EER, SEER, SEER2, HSPF, HSPF2, COP and kW/ton.
-
Heat Pump Balance Pt.
Find a heat pump's balance point from its 47 °F and 17 °F capacities and the…
NEW
-
CKV Exhaust Hood
Size commercial kitchen hood exhaust (cfm or l/s), hood length and make-up air from…
-
Reheat/Heating Sizing
Enter the airflow and the entering and leaving coil temperatures to size the reheat…
-
Wind Load
Uses ASCE 7-22 to calculate the lateral and uplift wind pressures on mechanical…
-
kW, HP, BTU, Ton…
Convert between tons, kilowatts (kW), horsepower (hp), Btu/h, MBH, lb-ft/h and…
Humidity/Psychrometrics
-
Condensate Generated
Calculate the condensate a coil generates from the entering and leaving air…
-
Condensate Pump
Size a condensate pump: calculate or enter the coil condensate, then list the pumps…
NEW
-
Dehumidifier Sizer
Size a dehumidifier from the latent load in pints/day, Btu/h or kW, and list the…
-
Fluid Mixing
Calculate the mixed temperature and specific heat of two fluids. Pick from the fluid…
-
VPD
Calculate the room and leaf vapor pressure deficit (VPD) for grow rooms from the…
-
Condensate Converter
Convert condensate and moisture between latent Btu/h, kW, pints per day, gallons per…
-
Psychrometric Chart
Enter two of dry bulb, wet bulb, dew point and RH% to get enthalpy, specific volume…
-
Psych Chart – 2 Cond.
Enter two air conditions to calculate total, sensible and latent cooling, condensate…
Economics
-
Annual Cooling Cost
Estimate the annual cost of running an air conditioner from its capacity, SEER or…
-
Break Even
Determine the break-even point based on the number of units, cost per unit, fixed…
-
Engineering Econ. (F/P,i,n)
Engineering economics calculator: solves for present worth (P), future worth (F)…
-
Home Price Comparison
Compare existing housing costs to the costs associated with a new home purchase
-
Capital Gains Estimator
Estimate federal long-term capital gains tax, net proceeds and cash on hand from a…
Electrical
Ohm's Law
Math
-
Bilinear Interpolation
Estimate a value between four known points on a grid, such as a reading between the…
-
Circle Sphere
Enter a circle's radius, diameter, area or circumference, or a sphere's volume or…
-
Linear Interpolation
Linear interpolation calculator: find y at a given x, or x at a given y, between two…
-
Temperature Converter
Convert temperatures between Fahrenheit, Celsius, Kelvin and Rankine.
Miscellaneous
Picture Hanger
Helpful Links
Manufacturer literature, codes and product-approval directories.