If you work from home in winter, the usual move is to bump the thermostat for the whole house — or to plug in a 1,500 W space heater at your feet — just to stop your toes and shins from going numb. Personal heat is the cheaper alternative: a heated foot mat, a flat-panel leg heater, or a heated throw that uses a fraction of the power and warms you, not every room. The catch is simple and we’ll repeat it: a desk heater only saves money if it lets you lower the central heat. Plugged in on top of your usual setpoint, it’s just another load. We’ll start with what you’d actually use, match the heater type to where you get cold, and cover the one step that creates the savings: turning the house down while you work. The safety basics are here too.
The savings come from the setback
Here’s the mechanism in plain terms. Your furnace, heat pump, or baseboard heat warms the air in the whole house (or zone) to the setpoint. A foot mat warms a small area in contact with you. If you hold the house a few degrees cooler during work hours and stay comfortable because of the mat, the heat you didn’t buy for the whole house is the saving, minus the mat’s small electricity use.
Three things decide whether it’s worth doing:
- Will you actually lower the setpoint? If not, skip this purchase — it only adds cost. If you will, pair it with a schedule on your thermostat so the setback happens automatically.
- How you heat. Expensive heat (electric resistance baseboard, propane, heating oil) makes a setback worth more. A line-voltage baseboard thermostat or room-by-room control lets you keep the office cooler without chilling everyone else.
- Where you’re cold. Cold feet on a cold floor are a contact problem — a mat fixes that cheaply. A draft across your ankles is an envelope problem — seal it with a door sweep or draft stopper before buying heat.
What’s not on the bill but still real: comfort, focus, and not fighting the household over the thermostat. We’ll mention those, not monetize them.
Check your home before you buy
Do this before you buy, or in your first week with a new unit.
- Read the label. Heaters list watts on the box or a rating label. The models in our shortlist range from about 90 W to 235 W. A typical portable space heater is 1,500 W on high.
- Find your rate. Use your bill’s all-in price per kWh (energy plus delivery), not just the “energy charge” line.
- Estimate a ceiling. Watts ÷ 1,000 × hours you’ll run it × rate. That assumes full power the whole time.
- Measure the real number. Plug the heater into a Kill A Watt for a full workday and read kWh. Units that cycle, or that you run on low, use less than the ceiling.
- Decide your setback. Pick how many degrees you’ll lower the house (or office zone) during work hours, and for how many hours. Write it down — it’s the whole point.
- Check it on the bill. Compare a few weeks of similar weather before and after. Weather swings make month-to-month comparisons noisy; utility interval data or degree-day comparisons are better if your utility shows them.
Example math only (not a promise): a 120 W mat × 8 hours = 0.96 kWh. At $0.17/kWh that’s about $0.16 a workday, roughly $3.50 over 22 workdays at full power. The same 8 hours with a 1,500 W space heater on high could reach 12 kWh (~$2.04 a day). Your setback savings depend on your heating system and climate and could be larger or smaller than the mat’s cost — we don’t publish a universal number because there isn’t an honest one. For the full 1,500 W vs 750 W cost math across ceramic, infrared, and oil-filled heaters, see space heater cost to run by type.
Product types at a glance
| Type | Typical draw (models listed) | Best for | Watch-outs |
|---|---|---|---|
| Heated foot mat (hard or carpeted) | ~90–135 W | Cold feet on hard or basement floors | Feet must stay on it; some get warm, not hot |
| Heated foot pad / soft warmer | Low-watt (check label) | Slippers-on comfort, budget | Softer pads can bunch; check auto-off |
| Flat-panel under-desk heater | ~150 W | Cold shins and knees under a desk | Works best within a short distance of legs; mixed reviews on output |
| Enclosed foldable leg warmer + blanket | ~150–235 W | Drafty rooms, very cold lower legs | Higher draw; feels enclosed; generic brands vary |
| Heated throw blanket | Low-watt (check label) | Lap and upper legs while seated | Cord routing; less handy at a standing desk |
| 1,500 W space heater | 1,500 W on high | Warming room air | Usually the opposite of a bill cut at a desk — see oil-filled heaters if you truly need room heat |
What to do first
Do these first
- Home office in a house you’d otherwise heat all day for one person. This is the core case: lower the whole-house setpoint during work hours, warm yourself.
- Expensive heating fuel. Electric resistance baseboard, propane, or oil makes every degree of setback worth more.
- Basement or slab-floor office. Cold floors are a contact problem; a mat is the cheapest fix.
- Household thermostat fights. One person who runs cold shouldn’t set the temperature for everyone.
These can wait
- You won’t change the thermostat. Then a heater only adds cost — buy fuzzy socks instead.
- Heat pump in mild weather. Heat is already relatively efficient; savings per degree are smaller. Still fine for comfort.
- A big draft is the real problem. Seal the door, window, or outlet first: weatherstripping, window kits, outlet gaskets.
- You’re rarely at the desk. Short sessions don’t justify a purchase.
What not to do
- Do not run a 1,500 W space heater through a power strip, extension cord, or light-duty smart plug. Follow the manual; most say wall outlet only.
- Do not leave personal heaters on while sleeping or away. Use units with auto-off or a timer.
- Do not cover a heater with blankets, papers, or bags, or pile things against it, unless the product is designed to be used with its own cover — and then use only that cover as directed.
- Do not use a unit with a damaged cord, scorch marks, or a hot-plastic smell. Unplug and replace it.
- Do not run the cord under a rug or across a walkway where it gets stepped on or pinched by chair casters.
- Do not rely on contact heat if you have reduced sensation in your feet (diabetes, neuropathy) without asking a clinician — burns can happen without you noticing.
- Do not buy heat to fix a draft. Seal first; heat second.
Which one should you buy?
- Will you lower the thermostat during work hours?
- No → skip the purchase, or buy only for comfort knowing it adds a little cost.
- Yes → continue, and set a schedule on your thermostat.
- Where are you cold?
- Feet only → heated foot mat. Go to step 3.
- Shins and knees under the desk → flat-panel heater. Go to step 4.
- Whole lower body in a drafty room → enclosed leg warmer or a mat + throw combo. Go to step 5.
- Lap and hands → heated throw (and maybe fingerless gloves).
- What’s under your feet? Hard floor or concrete → rigid or carpeted mat. Want the lowest draw → the 90 W option. Want more surface → the larger 135 W mat.
- How much room is under the desk? A panel needs a few inches of clearance and works best close to your legs; mount or stand it where you won’t kick it.
- Do you get up often? Enclosed warmers are cozy but slow to step out of; a mat plus throw is easier.
- Still unsure? Start with one foot mat and a Kill A Watt, try a 2–3°F setback for two weeks, and add a throw only if you’re still cold.
Size / spec notes (verify before checkout)
| Item | What to check | Why it matters |
|---|---|---|
| Watts | Rated wattage on the listing and label | Your running cost and outlet load |
| Auto-off / timer | Hours before shut-off | Protects against forgetting it on |
| Heat settings | Fixed vs adjustable | Fixed-output mats are simple; adjustable lets you run lower |
| Surface size | Mat dimensions vs your footwell | Too small and your feet slide off |
| Cord length | Distance to a wall outlet | Avoid extension cords |
| Safety listing | UL/ETL or similar on the listing or label | Basic third-party safety testing |
| Cleaning | Wipe-clean or removable cover | Mats get dirty under desks |
Our picks
We earn a commission if you buy through these Amazon links, at no extra cost to you. Check size and fit on the listing before you order.
Best overall foot matCozy Products Electric Foot Warmer (120 W)
A long-running, heavily reviewed under-desk foot mat at a modest wattage — the straightforward pick for cold feet on a cold floor while the house runs a few degrees cooler.
- Cozy Products Electric Foot Warmer Under Desk Office Heat Mat, 120 W Check price on Amazon
Lowest-watt pickCozy Products Toasty Toes (90 W)
The lowest draw in our shortlist. Good if your feet just need to be not-cold, and you want the smallest possible add to the bill.
- Cozy Products Toasty Toes Office Foot Warmer, 90 W Check price on Amazon
Larger mat: Cozy Products Super Foot Warmer (135 W) — more surface for people who shift around Check price on Amazon
Best for cold legsCozy Legs flat-panel heater (~150 W)
A thin radiant panel that warms shins and knees under a desk at about a tenth of a space heater’s high setting. Reviews are mixed on output — it works best positioned close to your legs — so treat it as a leg warmer, not a room heater.
- Cozy Products Cozy Legs Flat Panel Heater (new and improved) Check price on Amazon
Best for drafty roomsfoldable enclosed leg warmer with blanket (235 W)
Folding panels plus a blanket surround your lower legs and trap heat — the coziest option if your office floor gets a draft. It draws more than a mat (235 W rated) and comes from a less-established brand, so check the auto-off and return window.
- Foldable Leg Warmer with Soft Blanket, Under Desk Leg/Foot/Knee Heater, 235 W Check price on Amazon
Budget wide matheated floor mat for under the desk
A wider, lower-cost heated mat with adjustable temperature and a large review base — good if a rigid mat feels too small.
- Heated Floor Mat Under Desk Foot Warmer, wider, adjustable temperature Check price on Amazon
Best for lap warmthSunbeam heated plush throw
A heated throw with a personal controller, multiple heat settings, and auto-off — warm lap and thighs while seated, machine-washable after removing the controller per the instructions.
- Sunbeam Electric Heated Plush Throw, 50″ × 60″, 3 heat settings, auto-off Check price on Amazon
Must-have helperP3 Kill A Watt P4400
Turns “it’s low-watt” into a measured kWh-per-day number, and shows you exactly how much a 1,500 W space heater was costing by comparison.
- P3 P4400 Kill A Watt Electricity Usage Monitor Check price on Amazon
What we left out
- 1,500 W “personal” space heaters marketed for desks — they’re room heaters by wattage. If you genuinely need room heat, read our oil-filled heater guide for safer zone heating.
- USB-powered heated gadgets as a main heat source — fine for hands, too weak to replace a setback strategy.
- Disposable toe warmers for daily desk use — they work, but the trash and recurring cost add up.
- Invented ASINs or “save $X per year” claims.
Troubleshooting
| Symptom | Likely cause | Fix |
|---|---|---|
| Mat feels barely warm | Fixed low-output design, thick shoes, slow warm-up | Give it time to warm up; use socks or thin slippers; try the larger mat |
| Panel heater does nothing | Too far from your legs | Move it closer and aim it at your shins; it’s radiant, not a fan |
| Feet warm, legs still cold | Draft along the floor | Seal the door or outlet; add a throw; consider the enclosed warmer |
| Breaker trips | Heater shares a circuit with a space heater, printer, or kettle | Move to another circuit; never stack a space heater on the same outlet |
| Auto-off annoys you | Built-in safety timer | Restart it; don’t defeat the timer |
| Bill went up | Thermostat never moved | Make the setback on a schedule; measure the heater with a Kill A Watt |
| Hot smell or discoloration | Damaged unit or covered heater | Unplug immediately and replace |
| Cord gets pinched | Chair casters or desk legs | Re-route along the wall; use a cord cover, not a rug |
What this won’t fix
- It won’t help without a setback. Comfort, yes; savings, no.
- It doesn’t heat the room. Hands, shoulders, and the air you breathe stay at room temperature.
- It won’t fix drafts or insulation. If the floor is cold because of a crawl space or rim joist, see rim joist insulation and crawl space vent covers.
- Household setpoints have limits. Keep the house warm enough for pipes, pets, and anyone who’s elderly, ill, or very young.
- No universal number. Fuel type, rates, climate, and hours at home vary too much for honest “you’ll save $X” claims.
After you set it up
- Wattage and rate written down; ceiling cost per workday estimated
- One personal heater chosen for where you’re actually cold
- Kill A Watt reading for a full workday
- Thermostat schedule set a few degrees cooler during work hours
- Plugged directly into a wall outlet, cord routed safely
- Auto-off or timer confirmed; unit off at the end of the day
- Obvious drafts at the office door, window, and outlets sealed
Habits that help
- Dress for the setpoint. Wool socks and a layer let the mat run on low.
- Close the office door. On zoned or baseboard systems, heat only the room you’re in.
- Warm up before you sit. A quick walk beats cranking the heat.
- Use the schedule, not willpower. Program the setback once on your thermostat.
- Measure twice a season. Recheck kWh and compare similar-weather weeks.
FAQ
Does an under-desk heater or foot warmer actually lower my heating bill?
Only if it lets you turn the central heat down. A 90–150 W foot mat or panel heater uses a small fraction of a 1,500 W space heater, but it adds to your bill if the thermostat stays where it was. The savings come from the setback you make possible — for example, holding the house a few degrees cooler during work hours while your feet and legs stay warm. We do not guarantee a dollar figure; it depends on your heating fuel, rates, how much you lower the setpoint, and how many hours you work at home.
How much does a 120 W foot warmer cost to run?
Watts ÷ 1,000 × hours × your rate per kWh. Example math only: 120 W × 8 hours = 0.96 kWh; at $0.17/kWh that’s about $0.16 per workday, or roughly $3.50 for 22 workdays — if it ran at full power the whole time. Many units cycle or have low settings, so a plug-in watt meter like a Kill A Watt will show your real number. Compare that with a 1,500 W space heater on high: up to 12 kWh over the same 8 hours.
Is a heated foot mat better than a flat-panel under-desk heater?
They solve slightly different problems. A heated foot mat warms your feet by contact and is the lowest-watt option (roughly 90–135 W on the models we list). A flat-panel heater (Cozy Legs style, around 150 W) radiates heat at your shins and knees and works best close to your legs under a desk. Enclosed foldable leg warmers with a blanket trap heat around the lower legs but tend to draw more (one we list is rated 235 W). Cold feet only: mat. Cold legs under a drafty desk: panel or enclosed warmer.
Can I plug a foot warmer into a power strip or smart plug?
Follow the product manual first — many heater manufacturers say to plug directly into a wall outlet and not use extension cords or power strips. Never run a 1,500 W space heater through a power strip or a light-duty smart plug. Low-watt foot mats are a much smaller load, but the safest habit is a wall outlet plus the unit’s own auto-off timer. If you add a smart plug for a schedule, use one rated well above the device’s draw and only if the manual allows it.
Are under-desk heaters safe to leave on?
Treat them like any heating appliance: use them while you’re at the desk, not while you sleep or leave the house. Prefer models with auto shut-off or a timer, keep paper, blankets, bags, and pet beds from bunching against heating surfaces unless the product is designed for it, inspect cords for damage, and stop using any unit that smells hot, discolors, or has a damaged cord. People with reduced sensation in their feet (for example from diabetes or neuropathy) should ask a clinician before using contact heat.
Is a heated throw blanket a good alternative to a desk heater?
For lap and upper-leg warmth while sitting, yes — heated throws are typically low-watt and many have auto-off. They’re less convenient at a standing desk or if you get up often, and the cord can be a trip hazard across a walkway. Many people pair a foot mat for the floor with a throw for the lap and keep the room itself a few degrees cooler.
Related reading
- Space heater cost to run: ceramic vs infrared vs oil-filled — if you do need room heat, what 1,500 W really costs per hour by type
- Oil-filled space heaters / zone heating — when you truly need room air heat
- Heated mattress pads for zone heating — the overnight version of warming the person
- Best smart thermostats (2026) — schedule the work-hours setback
- Electric baseboard / line-voltage thermostats — keep one room cooler on baseboard heat
- Kill A Watt plug-in meter — measure the heater’s real kWh
- Plug-in thermostats for space heaters — if you do run a 1,500 W room heater, stop the dial overshoot
- Best weatherstripping and door draft stoppers — stop the ankle draft first
- Air sealing with caulk, foam & outlet gaskets — cold air from wall outlets near the desk
- Rim joist insulation — cold basement-office floors at the source
- Lower your electric bill: priority checklist — this-month order of operations
- Start Here — full suggested reading order
Bottom line
A heated foot mat or under-desk panel is one of the cheapest winter comfort buys — but it cuts your bill only when you lower the central heat because of it. Measure watts → pick mat, panel, enclosed warmer, or throw by where you’re cold → set a work-hours thermostat setback → plug into a wall outlet with auto-off → seal the draft under the desk. Skip 1,500 W “desk” heaters unless you genuinely need room heat. Amazon links may earn a commission as an Associate (disclosure). Return to Start Here or the priority checklist for order of operations.
Some links on this page go to Amazon, and we earn a commission if you buy, at no extra cost to you. Prices and savings vary by home and utility rate. More in our disclosure.
