Free HVAC Calculator – Instantly Estimate Room BTU Needs
Instantly estimate the required BTUs for heating or cooling your room. Includes expert tips, formulas, and answers to common questions.
HVAC Calculator
Enter your room dimensions to calculate required BTUs for heating or cooling.
How to Use the HVAC Calculator
Step-by-step guide to accurately calculate BTU needs for any room.
- Measure Room: Measure the length, width, and ceiling height of your room in feet.
- Enter Values: Input the length, width, and height into the calculator.
- Calculate: Click Calculate to see the required BTUs for your space.
- Adjust for Conditions: Increase BTUs for sunny rooms, kitchens, or high occupancy.
Quick HVAC Answers
Voice search and featured snippet optimized answers
How do I calculate HVAC BTU?
Multiply room length × width × height (in feet), then multiply by 25.
What is a BTU?
A BTU (British Thermal Unit) measures heating/cooling energy.
How many BTUs per square foot?
Typically 20-30 BTU per sq ft, but use cubic feet for accuracy.
Should I add extra BTUs?
Add 10-20% for kitchens, sunny rooms, or high ceilings.
HVAC Tips
- Add 10% more BTUs for kitchens or sunny rooms.
- Ceiling fans help distribute air more efficiently.
- Seal windows and doors to reduce energy loss.
- Consult a pro for large or multi-room spaces.
Frequently Asked Questions
How do I size an HVAC unit?
Calculate the required BTUs, then select a unit with matching or slightly higher capacity.
What if my room is irregularly shaped?
Break the space into rectangles, calculate each, then add together.
Does insulation affect BTU needs?
Yes, well-insulated rooms may need fewer BTUs.