Simple inputs
Answer only the questions needed to calculate a useful result.
Free HVAC calculators
UsefulHVAC calculators for clearer decisions
Turn HVAC questions into useful answers with simple calculators built for speed and clarity.
Choose a HVAC calculator, enter your numbers, and get an instant result with no account or unnecessary steps.
Free to use
Instant results
No sign-up
Immediate answers
See your result as soon as you are ready, without creating an account.
Practical context
Understand what the number means so you can make a better decision.
199 HVAC calculators
Choose a HVAC calculator and get a clear answer
Start with the question you need to solve. Every published HVAC calculator is collected here automatically, so the newest tools are always easy to find.
01
HVAC Runtime Calculator
Estimate daily HVAC runtime based on system capacity, average electrical draw, thermostat setpoint difference, outdoor climate severity, and home insulation quality.
Open calculator
02
HSPF Calculator
Estimate seasonal heating output and electricity use for a heat pump using HSPF, heating capacity, runtime, and electricity rate. HSPF is the…
Open calculator
03
HVAC kWh Calculator
Estimate HVAC electricity use in kilowatt-hours based on system power, daily runtime, seasonal usage, equipment efficiency, and climate demand.
Open calculator
04
HVAC Duty Cycle Calculator
Estimate HVAC duty cycle as the percentage of time a heating or cooling system runs during an observation period based on total…
Open calculator
05
Superheat Calculator
Calculate refrigerant superheat by subtracting the saturated evaporator temperature from the measured suction line temperature. This helps verify proper refrigerant charge and…
Open calculator
06
Subcooling Calculator
Calculate refrigerant subcooling by subtracting the measured liquid line temperature from the condensing saturation temperature. This helps evaluate whether a refrigeration or…
Open calculator
07
Superheat and Subcooling Calculator
Calculate either superheat or subcooling from measured refrigerant temperatures and pressures. Enter the saturated temperature corresponding to the measured pressure along with…
Open calculator
08
HVAC Temperature Split Calculator
Estimate the air conditioning temperature split by subtracting the supply air temperature from the return air temperature. This helps evaluate basic cooling…
Open calculator
09
Sensible Heat Ratio Calculator
Calculate the sensible heat ratio (SHR) for an HVAC process using sensible cooling load and latent cooling load. SHR indicates the fraction…
Open calculator
10
HVAC Enthalpy Calculator
Calculate the specific enthalpy of moist air for HVAC applications using dry-bulb temperature, relative humidity, and altitude. The result estimates air enthalpy…
Open calculator
11
HVAC COP Calculator
Calculate the coefficient of performance (COP) for an HVAC system using heating or cooling output and electrical power input. COP is the…
Open calculator
12
HVAC Efficiency Calculator
Estimate HVAC system efficiency using cooling output, electrical power use, seasonal runtime, climate factor, and system age. This calculator approximates effective seasonal…
Open calculatorHow it works
From question to answer in three small steps
Each HVAC calculator is designed to keep the process short, understandable, and useful from the first input to the final result.
Pick the right tool
Choose the HVAC calculator that matches the question or decision in front of you.
Add your numbers
Enter the few details needed for a result tailored to your situation.
Use the result
Review the answer and supporting context, then move forward with more confidence.
Made to be useful
Better HVAC decisions start with clear numbers
A good HVAC calculator should do more than produce a number. It should make the inputs easy to understand, present the result clearly, and help you see what to do next.