Heat Pump Calculator
Fast, accurate, and free online Heat Pump Calculator tool that runs directly in your browser.
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Heat Pump Calculator
Advanced analysis of energy efficiency and heating costs of renewable energy
Enter the data on the left to generate a full energy report.
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Other tools you may find usefulHeat pump calculator - calculate power, electricity consumption and real heating costs
A heat pump can be brilliantly cheap to operate... but only if it is matched to the building and operating conditions. This calculator helps you quickly estimate the required heating power, electricity consumption, costs (day / month / season) and several "premium" indicators that are often missing in simple calculations: the cost of 1 kWh of heat, the percentage of savings vs the heater, and even an approximate buffer in liters.
The best thing about this tool is that you don't have to start with the installation design or do a PhD in building physics. You enter a few numbers, choose the house standard, set the temperatures and COP - and the calculator spits out a clear, practical answer: how many kW you need at the peak, how much electricity it will "eat" and how much it costs at your price per kWh.
What exactly will you calculate in this calculator
The result does not end with "pump power X kW". You get a set of metrics that help you plan your budget and assess whether the parameters look healthy:
- Heating power (kW)– peak demand for a given temperature difference.
- Power consumption (kW)– with COP set.
- Energy consumption (kWh)– daily and monthly (depending on working time).
- Cost per day and month– at your energy price (PLN/kWh).
- Season estimate– approximate (based on monthly cost).
- Cost of 1 kWh of heat- i.e. "how much do you pay for heat", not for electricity.
Why is this result "more realistic"
In practice, the heat pump works in variable conditions, and houses differ in standard and ventilation. Therefore, the calculator takes into account factors that make a difference in costs:
The building standardtranslates into base losses (W/m²), andtemperature difference (ΔT)scales the result to current conditions. Additionally, there is a correction for the height of the rooms and the type of ventilation. Effect? You get an estimate that is closer to "real life" than simply multiplying square footage by one constant.
How to use it - simple, without any fuss
If you want to get a reasonable result, I would stick to one rule: enter the data as you would actually live in this house. Temperature "for show" and COP "from the folder" can produce beautiful numbers... but then the calculation verifies the fantasy.
- Enter area (m²) i height. Height matters - because 120 m² with a 2.6 m ceiling is a different volume than 120 m² with 3.2 m.
- Select the building standard(passive / modern / medium / old). This is an abbreviation that replaces the initial heat loss audit.
- Set the temperature inside i outside. The difference (ΔT) drives the entire calculation.
- Enter COPandelectricity price. COP is your cost lever - even a small change can change the result by several percent.
- Set the daily working time. It is not "how long the pump should work", but how long it will actually have to provide energy during the day under given conditions.
What the results mean and how to read them without stress
The calculator shows several numbers - and each of them has a different application. In short:heating powerhelps you assess whether your appliance will be undersized, andconsumption and cost ofhelp you manage your bills. The rest are "tastes" that often do the job when comparing offers.
Heating power (kW)
This is an estimate of the peak demand at the set outdoor temperature. If you set -10°C, the calculator replies: "under these conditions, the house needs approximately X kW of heat to maintain the temperature inside." In practice, this number is a reference point for selecting pump power (with or without reserve, depending on the strategy and peak source).
Power consumption (kW) and consumption (kWh)
This is where the COP magic happens. If the house needs 6 kW of heat and your COP is 3, the pump will consume about 2 kW of electrical power to "produce" these 6 kW. Then comes the operating time: 2 kW × 8 h = 16 kWh/day. And you already know whether it will be 300 kWh or 900 kWh per month.
Costs: day, month and season
Costs are calculated from your price for 1 kWh of energy. This is the most "real" part of the calculator, because it gives you the answer: how much money will disappear from your account with a given heating style. Additionally, you get an estimate of the season - an approximation useful for comparing options (e.g. pump vs. gas vs. heater).
Cost of 1 kWh of heat
This is my favorite indicator because it is brutally honest. If electricity costs PLN 1.20/kWh and COP is 3.2, then 1 kWh of heat costs approximately PLN 0.38. And this is a number that you can compare with other heat sources.
Building standard - where the losses in W/m² come from
In the calculator, the house standard translates into the base value of losses (W/m²). This is a simplification - but very useful. Thanks to this, you can "flip" scenarios: what if I add insulation? what if I replace the windows? what if it's an old house without insulation?
| Building standard | Base value (W/m²) | How to understand it in practice | Who is it suitable for |
|---|---|---|---|
| Passive | 15 | Very low losses, low power requirement even in frosts. | Houses with heat recovery, excellent insulation, perfect details. |
| Modern (WT2021) | 40 | New construction, reasonable insulation and windows - the result is usually "on point". | New houses and fresh modernizations with insulation. |
| Medium (2000+) | 70 | A typical house that is "somehow" insulated, but not perfect. Often a real compromise. | Many buildings from the late 90s/early 00s and later. |
| Old (without insulation) | 120 | Large losses – power and costs increase quickly. Here, insulation can be the best investment. | Older buildings without thermal modernization, with thermal bridges. |
“Premium” stats: what they are for and how they help you decide
In addition to the base numbers, the calculator shows several metrics that are great for comparing scenarios. You don't have to use them, but if you plan to buy a pump or analyze your bills after installation - they can save you a lot of nerves.
CO₂ emissions (kg/month)
An approximation of emissions resulting from electricity consumption. Perfect if you count the "footprint" or compare heat sources from an environmental perspective.
Savings vs. heater
Percentage difference in the cost of providing heat at a given COP. The higher the COP, the greater the advantage over a pure electric heater.
Buffer (L)
Approximate buffer capacity calculated "based on power". It helps you get the scale before you get into the installation project.
Performance Label
A simple description of whether the COP looks healthy. This will not replace the website, but it gives a quick signal: "great", "okay", or "something is wrong here".
Common usage scenarios (yes, that makes sense)
People use a calculator in different ways - and in most cases the goal is the same: make decisions faster. Below are some common situations where the result really comes in handy.
Before buying a pump
Do you want to check whether 8 kW makes sense or is it too much? You enter the square footage, standard and temperatures. You get peak power and can talk more sensibly with the contractor. There is no risk that someone will sell you a device by sight.
Tip: count two variants - "normal winter" outdoor temperature and "frost of the century". The difference can be instructive.
After installation to deal with the bills
You already have a pump, but the bills surprise you? Compare: what ΔT you set, what real COP you have in the season and how many hours a day the system works. Sometimes the problem is not in the device, but in the settings, heating curve or ventilation.
Instead of guessing what is "consuming electricity", you get numbers from which you can start sensible diagnostics.
A little cheat: what influences the cost of heating the most
If you have the impression that all this is complicated, that's cool. In practice, three things do the most work: building standard, temperature difference and COP. The rest perfects the result.
- COP– an increase from 2.8 to 3.5 is often a tens of percent difference in costs.
- Outdoor temperature– the colder it is, the higher the demand and usually the lower the COP.
- House standard- insulation can be an "invisible heat pump" because it reduces the needed power.
- Working time– in the same house you can have 6 h/day or 14 h/day (depending on habits and settings).
- Energy price– obvious, but worth updating, because this is the easiest place to make an error in calculation.
FAQ – questions that appear most frequently
Is this calculator suitable for selecting the heat pump power "to 100%"?
It's great for pre-evaluating and comparing scenarios, but it won't replace design. The calculator is based on simplified assumptions regarding heat losses and their scaling with ΔT. This is enough to estimate the order of magnitude and filter out extremely inappropriate proposals, but the final selection should take into account, among others: heating installation, domestic hot water preparation, operating parameters, climate zone and the nature of the building.
How should I set the COP if the manufacturer provides different values?
It is most reasonable to adopt COP "from conditions similar to yours". The COP depends on the source temperature and the supply temperature (the higher the supply temperature, the lower the COP is usually). If you use underfloor heating, the COP may be better than with radiators requiring higher temperatures. If you are not sure, count two variants: cautious (lower COP) and optimistic (higher COP) - you will see cost ranges instead of one "magic" number.
Why does the result increase significantly when I change the outside temperature?
Because the heat demand increases with the temperature difference between the inside and outside (ΔT). When it gets much colder outside, the building loses heat faster, so the system must supply more of it. It's normal that the difference between -5°C and -15°C can significantly change the peak power - and that's why it's worth considering several scenarios, especially if you live in a colder region.
Is "operating time per day" the same as compressor operation?
Not always. In practice, the heat pump can modulate power, take breaks, work more intensively at a cheaper tariff or heat hot water in specific time windows. Treat the working time slider in the calculator as a simple way to calculate energy per day under given conditions. If you have data from the meter or the application (how many kWh per day), you can also do the opposite: adjust the operating time so that the result from the calculator is close to real consumption, and then test the impact of changes in COP or temperatures.
Where does the "performance label" come from and can I trust it?
This is a simplified classification based on COP thresholds - it is intended to give a quick signal whether the set COP value looks good. Treat it as a guide, not a diagnosis. Low COP may result from real conditions (e.g. very low source temperature or high power supply), but may also suggest that the installation is not optimally set or requires service. If you see consistently low COP during the season, it is worth checking the operating parameters, filters, settings and plumbing of the system.
How to interpret CO₂ emissions and the "number of trees"?
This is an educational and comparative element. Emissions are calculated based on the average coefficient for electricity, so they do not reflect fluctuations in the energy mix over time. The "number of trees" is an even more illustrative calculation to help you feel the scale - it is not a hard environmental metric. If you need accurate data for the report, it is better to rely on current indicators and methodology for calculating the carbon footprint for a specific case.
Can I compare a heat pump with gas or pellets with this calculator?
Yes – but indirectly. The most useful indicator will be the cost of 1 kWh of heat. Having the cost of heat from the pump (electricity price / COP), you can compare it with the cost of heat from other sources, taking into account their efficiency and fuel price. Just remember that in the real world there are also fixed costs, service, tariffs, and sometimes also comfort and maintenance-free operation, which cannot be summed up in one category.
Calculate your scenario and write down the result
If you are hesitating between two settings (e.g. COP 3.0 vs. 3.7 or "medium" vs. "modern" standard), make two calculations in a row and compare the monthly cost and the cost of 1 kWh of heat. It's the fastest way to see what really matters.
Run the calculator and calculate the costs