Underfloor Heating Calculator UK – What System Do I Need? - Eco Friendly Heating
What Underfloor Heating Do I Need?
A simple room-size calculator to help you choose the right electric underfloor heating system for your project.
Trying to work out which electric underfloor heating system is right for your room? This simple underfloor heating calculator helps you compare the main options based on room size, floor type and project style. It is designed to make choosing between foil heating, carbon film, heating mats, loose wire, DCM-PRO and in-screed systems much easier.
Whether you are renovating a bathroom, upgrading a kitchen, fitting heating beneath laminate flooring or planning a new extension, this page is here to help you narrow down the most suitable system before you buy.
Quick Links
Choose your preferred system, enter your room size, subtract any floor area covered by fixed units if needed, and the calculator will suggest the type of setup, likely wattage band, essential extras and suitable products to look at next.
Choose Your System and Room Size
Foil Heating
Best for floating floors, renovations, bathrooms and low-build projects.
Carbon Film
Best for laminate and engineered wood in dry rooms with low build-up.
Heating Mats
Best for tiled bathrooms, kitchens and regular-shaped rooms.
Loose Wire
Best for irregular room layouts and awkward tiled areas.
DCM-PRO
Best for tiled floors where decoupling and tile protection matter.
In-Screed
Best for new builds, extensions and deeper floor build-ups.
This is a simplified planning estimate. Real performance and running costs depend on insulation, thermostat settings, floor finish, subfloor condition and how much of the floor is truly heated.
Need a more exact whole-room heating calculation? A larger heat loss calculator and guide will be added separately for more advanced planning.
Electric Underfloor Heating Systems Compared
| System | Best For | Typical Floors | Build Height | Main Advantage |
|---|---|---|---|---|
| Foil Heating | Floating floors and renovations | Laminate, engineered wood, some vinyl/carpet builds | Very low | Fast, dry installation |
| Carbon Film | Large floating floor areas | Laminate, engineered wood | Ultra low | Wide radiant heating surface |
| StickyMat / Heating Mats | Bathrooms, kitchens, tiled rooms | Tile, stone | Low | Quick installation |
| Loose Wire | Irregular layouts | Tile, stone | Low | Flexible routing around obstacles |
| DCM / Decoupling | Tile protection + heating | Tile, stone | Low | Helps reduce tile cracking risk |
| In-Screed Cable | New builds / major renovations | Tile, stone, screeded floors | High | Excellent long-term heat distribution |
If your floor is tiled, the most common choices are StickyMat heating mats, loose wire systems and DCM-PRO decoupling heating. For floating floors such as laminate or engineered wood, foil heating and carbon film are normally the best match. If you are building an extension or new home, in-screed electric underfloor heating can provide very even heat distribution across the whole floor.
Your Suggested System Path
Foil Heating Recommendation
Foil heating is a strong option where you want a dry, low-build installation beneath floating floors. It is especially useful for laminate, engineered wood and some bathroom-friendly overlay builds where screed is not practical.
You will usually also need: insulation below, thermostat with floor sensor, and if the final floor is vinyl, carpet or linoleum, an overlay system above the foil.
A dry installation foil system designed for floating floors such as laminate and engineered wood.
A foil heating mat designed to spread warmth evenly under laminate and similar floating floors.
Insulation below the foil helps improve warm-up speed and reduce wasted heat.
Carbon Film Recommendation
Carbon film is ideal for floating laminate or engineered wood floors where build-up needs to stay very low. It is particularly useful in larger dry rooms and projects where a broad radiant heating surface is preferred.
You will usually also need: insulation below, thermostat, vapour barrier, connection crimps, insulation disks and supporting accessories.
A complete low-profile carbon film heating solution for floating floors.
A flexible carbon film option for tailored room layouts and floating floor projects.
Used above EcoFilm to help protect the system from moisture and friction.
Heating Mats Recommendation
Heating mats are usually the easiest tiled-floor option for bathrooms, kitchens and regular-shaped rooms. The pre-spaced cable makes installation quicker and tidier than laying wire manually.
You will usually also need: insulation boards, thermostat and floor sensor, primer where needed, and flexible adhesive or levelling compound.
A quick-install mat system for tiled bathrooms, kitchens and regular-shaped rooms.
A practical mat system for tiled floors where fast installation matters.
Insulation boards below the mat can improve warm-up times and reduce wasted heat.
Loose Wire Recommendation
Loose wire systems are best where your room has awkward layouts, sanitaryware, islands or obstacles. They offer greater freedom in cable routing than pre-spaced mats.
You will usually also need: insulation boards, thermostat, fixing strips or clips, primer where needed, and adhesive or levelling compound.
Flexible installation around fixtures and complex layouts.
Ideal where you need maximum layout flexibility under tiles.
Helps secure loose wire cable runs during installation.
DCM-PRO Recommendation
DCM-PRO and heated decoupling systems are ideal where you want tile heating plus improved protection against subfloor movement. They are especially useful in bathrooms, kitchens and premium tiled renovation projects.
You will usually also need: matching cable, thermostat, floor sensor, adhesive and the correct tile build-up. Insulation boards may still be recommended below the system.
Combines heating with tile protection and quick installation.
Ideal where a traditional fleece-backed decoupling build-up is preferred.
The heating cable used within DCM-Pro decoupling systems for tiled floor installations.
In-Screed Recommendation
In-screed systems are designed for new builds, extensions and major renovation projects where the heating cable is laid into a screed layer. They are ideal when you want durable whole-floor heating with excellent long-term heat distribution.
You will usually also need: insulation below screed, thermostat, floor probe, vapour control where required, fixing rails or strips and the correct screed build-up.
A robust solution for screeded floors and larger projects.
A practical in-screed cable solution for larger heated floor areas.
What Else Do I Usually Need?
| System | What Else You Usually Need |
|---|---|
| Foil Heating | Insulation boards or insulated underlay, thermostat with floor sensor, aluminium/fixing tape, and if using vinyl, carpet or linoleum, overlay boards. |
| Carbon Film / EcoFilm | Insulation below, thermostat, vapour barrier, connection crimps, insulation disks, cold tail leads, adhesive tape, and often a crimp tool unless included in a kit. |
| StickyMat / Heating Mats | Insulation boards, thermostat, floor probe, primer where needed, flexible tile adhesive or levelling compound, and suitable electrical protection. |
| Loose Wire | Insulation boards, thermostat, floor probe, fixing strips or clips, tape, primer where needed, and adhesive or levelling compound. |
| DCM / Decoupling | Decoupling mat, matching cable, thermostat, floor probe, primer if required, adhesive, and the correct tile build-up. |
| In-Screed Cable | Insulation below screed, thermostat, floor probe, vapour barrier / DPM where required, perimeter strip, fixing rails or strips, and the correct screed build-up. |
Best place to buy everything you need? A store that supplies not just the heating, but the boards, accessories, thermostats and practical build-up items too. That’s exactly why you can build a more complete project basket with Eco Friendly Heating and Flooring.
Helpful Guides
Not sure which system is best? These guides explain the main differences, installation build-ups and running cost considerations:
How to Use This Calculator Well
4 Simple Steps
Start with the floor type and project style rather than overthinking wattages immediately.
Enter room length and width, then subtract areas covered by fixed units if needed.
Most projects need more than just the heating system, especially insulation and a thermostat.
Each system has its own buyer guide and running cost page to help you decide with more confidence.
Frequently Asked Questions
What underfloor heating system is best for laminate flooring?
Foil heating and carbon film are usually the main systems to compare for floating laminate and engineered wood floor installations.
What underfloor heating system is best for tiled bathrooms?
Heating mats, loose wire and DCM-PRO are usually the most relevant options for tiled bathrooms, depending on the room shape and build-up.
Do I need insulation under electric underfloor heating?
In most projects, yes. Insulation helps reduce heat loss into the subfloor and usually improves warm-up times and efficiency.
Do I need a thermostat with electric underfloor heating?
Yes, almost always. A thermostat with a floor sensor helps control temperature, improve comfort and protect the floor finish where temperature limits matter.
What is the easiest underfloor heating system to install?
For tiled floors, heating mats are often one of the easiest options because the cable is already pre-spaced. For floating floors, foil heating is often one of the simplest dry-install systems.
Can electric underfloor heating be used as the main heating in a room?
Yes, in some rooms it can. This depends on the insulation level, room heat loss, system output and floor finish.
Ready to Buy Underfloor Heating?
Once you know which system suits your room best, the next step is choosing the right heating kit, insulation, thermostat and accessories. You can compare our main systems below or read the detailed buyer guides for each one before ordering.