What Size Heat Pump Do I Need (Heat Pump Size Calculator)

Sizing your Heat Pump

Properly sizing a heat pump is essential for it to efficiently do its job. Let’s break that down:

Efficiently: Only a heat pump of the right size is most efficient. Too big or too small, and energy will be wasted, and your electric costs will be too high.

Doing its job: The heat pump will keep your home cool and dehumidified in summer and plenty warm in winter without “overdoing” it.

You know all this, and that’s why you’re here at the Pick HVAC Heat Pump Size Calculator.

Home size, climate, insulation level and how much sun your house receives are the factors in answering, “what size heat pump do I need?”

The heat pump size calculator is accurate. We also include a variety of Heat Pump Sizing Tables and home-size examples you can use for quick reference or to double-check the results you get from the calculator.

Heat Pump Size Calculator

The heat pump sizing calculator is easy to use, even without explanation. But we provide additional information for a more thorough understanding of heat pump sizing and quick references for common questions like:

  • How many btu do I need for a 1500 square foot house?
  • What size heat pump do I need for a 2000 sq ft home?
  • What size heat pump do I need for a 2500 square foot house?
  • Is my home too big for a single heat pump?
  • Should I use a heat pump for heating in Zone 6? Zone 7?

Here is the top-rated heat pump size calculator from the pros at Pick HVAC.

We walk you through the steps in the content below the sizing calculator.

Heat Pump Size Calculator

See local cost of
30,000 BTU heat pump

4 Step Heat Pump Sizing Calculator

This explanation will give you confidence you’re putting the right information into the heat pump sizing calculator – in case you have concerns about how to do it.

Step 1 – Climate Zone

Find where you live, and enter the Zone number.

I’m near the edge of a zone! Use the warmer Zone. It’s better to have a little too much AC power in summer than too little. For example, the Dallas / Ft. Worth area is near the boundary between Zones 2 and 3. We recommend using Zone 3 for that area.

I live in Zone 6! I live in Zone 7!

Brrr! Our recommendation for homeowners in those cold regions is to skip the heat pump.

Instead, install an efficient gas furnace. If you also want AC, add the equipment needed – the condensing unit outside and the indoor coil plus refrigerant lines, etc. See our Central Air Conditioner Guide for full details on your options, sizing and cost. 

Step 2 – Home Size

Type in the number of square feet in your home – all heated and cooled areas. If you supply heat and AC to the basement, include the square footage. If not, then don’t. Pretty simple.  

The details of home size are the same as what we say on our Gas Furnace Size Calculator page. The information works for heat pump sizing too.

Calculating square feet: If you are unsure of your home’s square footage, you can locate it on a blueprint/house drawing or in closing documents.

For exact measurements, you have two options that will work well enough.

First – The most accurate way is to calculate the square footage of each room and add the numbers together. Measure the length x width of each. For example, a room 24 feet long and 15 feet wide is 360 square feet.

Secondly – A method that also yields an accurate calculation is to measure the footprint of your home. A simple rectangle is easiest. For example:

50 feet long x 30 feet wide = 1,500 square feet

If it’s a two-story with that footprint, double the calculation to 3,000 square feet.

When there are 6 or more corners on the house, the calculation is a little trickier. Break down the home into rectangles. Measure/calculate the sections separately, and add them together.

Consider a six-sided home. Let’s say the main body is 50 x 30, as in the example above. That’s 1,500 square feet. And there is an addition or extension that is 25 x 20, or 500 square feet. Add the sections for a total of 2,000.

Step 3 – Insulation Condition

This is fairly simple too. Here are your options with a description of each. Choose the one that best fits your home.

Good: Your home is fairly new, or it has been updated with house wrap, increased insulation in the attic and/or new energy efficient doors and windows.

Average: Your home is vintage 1990 to 2010, and not much has been done to make it more energy efficient. The “average” rating would also apply to a home built before 1990 with some energy efficient updates in place such as added insulation or better windows.

Poor: Your home is old and hasn’t been updated. Windows and doors are drafty, and some rooms are colder than the rest of the house in winter and hotter in summer.

Step 4 – Sun Exposure

Sun helps in winter and hurts in summer. And you want a heat pump that will keep your home comfortable on the most extreme temperature days.

A sunny home in summer and a fully shaded home in winter will need more heat pump power.

Results – Recommended Heat Pump Size

Our heat pump sizing calculator gives you the amount of heating and cooling you need for your climate.

If you want to conserve energy, or you don’t mind wearing a sweater in the house in winter, then choose a unit toward the lower end of the range.

If you want to be sure your indoor climate will be comfortable all year, then choose a heat pump size near the upper end of the range.

Here are heat pump sizes in tons and BTUs, so you’ll know what size to select.

  • Up to 18,000 BTU = 1.5 ton heat pump
  • 18,000 to 24,000 BTU = 2 ton heat pump
  • 24,000 to 30,000 BTU = 2.5 ton heat pump
  • 30,000 to 36,000 BTU = 3 ton heat pump
  • 36,000 to 42,000 BTU = 3.5 ton heat pump
  • 42,000 to 48,000 BTU = 4 ton heat pump
  • 48,000 to 60,000 BTU = 5 ton heat pump

Checking Your Results – Sample Heat Pump Sizing Tables

> Use the Pick HVAC Heat Pump Sizing Calculator for most accurate results.

> Use these Heat Pump Sizing Tables to check your results compared with the most common results readers get.

What Size Heat Pump Do I Need for 1500 Square Foot House?

  • Hot Climate: 40,000 BTU (3.5 Ton Heat Pump)
  • Warm Climate: 33,000 BTU (3 Ton Heat Pump)
  • Cool Climate: 28,000 BTU (2.5 Ton Heat Pump)

What Size Heat Pump Do I Need for 2000 Square Foot Home?

  • Hot Climate: 52,000 BTU (4.5 Ton Heat Pump)
  • Warm Climate: 44,000 BTU (4 Ton Heat Pump)
  • Cool Climate: 38,000 BTU (3.5 Ton Heat Pump)

What Size Heat Pump Do I Need for 2500 Square Foot House?

  • Hot Climate: 65,000 BTU (5.5 Ton Heat Pump)
  • Warm Climate: 55,000 BTU (5 Ton Heat Pump)
  • Cool Climate: 48,000 BTU (4 Ton Heat Pump)

Detailed Heat Pump Sizing Chart by Square Footage

Heat Pump Sizing Chart by Room or home Size (sq ft):

Home SizeHeat Pump Size (BTU)Heat Pump Size (Ton)
1,000 sq ft18,000 BTU1.5 Ton
1,200 sq ft24,000 BTU2 Ton
1,500 sq ft36,000 BTU3 Ton
1,600 sq ft36,000 BTU3 Ton
1,800 sq ft42,000 BTU3.5 Ton
2,000 sq ft48,000 BTU4 Ton
2,500 sq ft54,000 BTU4.5 Ton
3,000 sq ft60,000 BTU5 Ton

Many large homes in Zones 1 to 5 have more than one heat pump. A single 60,000 BTU (5 ton) central heat pump or 48,000 BTU (4 ton) mini split heat pump doesn’t have enough capacity to do the job in summer. There is just too much heat to move. 

The answer is to determine how many total BTUs of heating and/or cooling you need, and to figure the best way to divide up your home into two zones, each served by a separate heat pump. 

This is where choosing a trained and experienced heat pump installer helps. Use the toll-free number on this page or the Free Local Quotes option to get in touch with local, licensed and insured heat pump installers. They will provide free estimates at no cost or obligation to you. 

Heat Pump by the Ton

If you’re more familiar with heat pump sizing by the ton, this Heat Pump Sizing Chart will help. 

Heat Pump SizeSquare footage forHot Climate(Zone 1&2)Square footage forWarm Climate(Zone 3)Square footage forModerate Climate(Zone 4 & 5)
1.5 ton600-800 sq ft700-1000 sq ft800-1,100 sq ft
2 ton800-1,000 sq ft1,000-1,200 sq ft1,100-1,500 sq ft
2.5 ton1,000-1,300 sq ft1,200-1,500 sq ft1,500-1,800 sq ft
3 ton1,300-1,600 sq ft1,500-1,800 sq ft1,800-2,000 sq ft
3.5 ton1,600-1,800 sq ft1,800-2,000 sq ft2,000-2,500 sq ft
4 ton1,800-2,000 sq ft2,000-2,400 sq ft2,500-3,000 sq ft
4.5 ton2,000-2,400 sq ft2,400-2,700 sq ft3,000-3,300 sq ft
5 ton2,000-3,000 sq ft2,700-3,000 sq ft3,300-3,700 sq ft

Written by

Rene has worked 10 years in the HVAC field and now is the Senior Comfort Specialist for PICKHVAC. He holds an HVAC associate degree and EPA & R-410A Certifications.

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