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stop guessing what winter will cost you
most rvers have no idea what they spend on heat until they’re refilling propane tanks every 10 days and doing math on a gas station receipt. i made that mistake my first winter. $270 in december alone, just for heat. i had no budget because i’d never calculated it beforehand.
this article gives you the exact formulas, real 2026 fuel prices, and a complete calculator framework so you know your heating costs before you leave home. plug in your numbers. plan your budget. no surprises at the propane station.
for the complete winter setup beyond just heating costs, our winter boondocking survival guide covers gear, batteries, insulation, and locations together.
the three variables that determine your heating cost
variable 1: your furnace BTU rating
find your furnace nameplate (usually inside furnace access panel or rv owner’s manual). note the BTU output rating.
common rv furnace sizes:
- 16,000 BTU: small trailers, van conversions (under 22 feet)
- 25,000 BTU: mid-size trailers and class B (22-28 feet)
- 30,000 BTU: standard trailers and class C (26-32 feet)
- 35,000 BTU: large trailers and motorhomes (30-38 feet)
- 40,000 BTU: large class A and fifth wheels (35-45 feet)
if you have a diesel heater, note its watt rating (5KW = 17,000 BTU, 8KW = 27,300 BTU).
variable 2: overnight low temperature at your destination
this determines how hard your heater works. the relationship is not linear: dropping from 40°F to 30°F increases propane consumption roughly 25%. dropping from 30°F to 20°F increases it another 40%. extreme cold is disproportionately expensive.
temperature reference by location (january average overnight lows):
- quartzsite, arizona: 34°F
- phoenix, arizona: 44°F
- tucson, arizona: 38°F
- caballo lake, new mexico: 28°F
- big bend, texas: 32°F
- florida panhandle: 44°F
- yuma, arizona: 42°F
variable 3: current fuel prices
propane prices (february 2026 averages):
- refill station (pilot, loves, uhaul): $2.85-3.15/gallon
- walmart propane exchange: $4.50 for 20-lb tank (avoid, expensive)
- costco refill (membership required): $2.55-2.75/gallon
- small vendors at campgrounds: $4.00-5.50/gallon (avoid)
diesel prices (february 2026 averages):
- pilot travel center: $3.05-3.30/gallon
- loves travel stop: $3.00-3.25/gallon
- standard gas station: $3.15-3.45/gallon
electricity (if shore power available):
- rv park included in site fee: $0/kWh (effectively free)
- metered electricity: $0.12-0.22/kWh (national range)
- national average: $0.167/kWh
propane heating cost calculator
the formula
nightly propane cost = (BTU rating ÷ 91,500) × duty cycle × hours × price per gallon
where:
- BTU rating = your furnace output in BTU/hour
- 91,500 = BTU per gallon of propane (fixed constant)
- duty cycle = percentage of time furnace runs (see table below)
- hours = overnight hours furnace operates (typically 8-10 hours)
- price per gallon = what you actually pay at refill
duty cycle reference table
| exterior overnight low | duty cycle (approx.) |
|---|---|
| 45°F | 30-40% |
| 40°F | 40-50% |
| 35°F | 50-60% |
| 30°F | 60-70% |
| 25°F | 70-80% |
| 20°F | 80-90% |
| 15°F | 90-100% |
| below 10°F | 100% (continuous) |
note: duty cycle varies by rv insulation quality. poorly insulated rvs (single-pane windows, no skirting, gaps in weather stripping) run 10-20 percentage points higher than these figures. properly insulated rvs run 10-20 points lower.
worked examples
example 1: quartzsite beginner setup
- furnace: 30,000 BTU
- average overnight low: 34°F
- duty cycle: 58% (from table, 35°F)
- overnight hours: 9
- propane price: $3.00/gallon
calculation: (30,000 ÷ 91,500) × 0.58 × 9 × $3.00 = 0.328 × 0.58 × 9 × $3.00 = $5.13/night
monthly cost: $5.13 × 30 = $153.90/month
example 2: caballo lake moderate setup
- furnace: 35,000 BTU
- average overnight low: 28°F
- duty cycle: 68% (between 30°F and 25°F values)
- overnight hours: 10
- propane price: $2.98/gallon
calculation: (35,000 ÷ 91,500) × 0.68 × 10 × $2.98 = 0.383 × 0.68 × 10 × $2.98 = $7.76/night
monthly cost: $7.76 × 30 = $232.80/month
example 3: cold snap scenario (20°F nights)
- furnace: 35,000 BTU
- overnight low: 20°F
- duty cycle: 88%
- overnight hours: 10
- propane price: $3.10/gallon
calculation: (35,000 ÷ 91,500) × 0.88 × 10 × $3.10 = 0.383 × 0.88 × 10 × $3.10 = $10.44/night
monthly cost: $10.44 × 30 = $313.20/month
four-month winter propane cost estimates
using 35,000 BTU furnace, $3.00/gallon propane, 10-hour nights:
| location | avg overnight low | nightly cost | 4-month total |
|---|---|---|---|
| phoenix AZ | 44°F | $3.77 | $452 |
| quartzsite AZ | 34°F | $5.75 | $690 |
| big bend TX | 32°F | $6.14 | $737 |
| caballo lake NM | 28°F | $7.56 | $907 |
| cold snap (20°F) | 20°F | $10.44 | $1,253 |
these are heat-only costs. add $100-150/month for propane cooking, hot water, and refrigerator (if propane fridge) to get total propane budget.
diesel heater cost calculator
the formula
nightly diesel cost = fuel consumption rate × hours × price per gallon
chinese 5KW diesel heater consumption rates by setting:
- low (1KW): 0.04 gallons/hour
- medium-low (2KW): 0.09 gallons/hour
- medium (3.5KW): 0.21 gallons/hour
- high (5KW): 0.40 gallons/hour
most winter boondockers run medium to medium-high for overnight heating. continuous medium setting (0.21 gal/hour) is the most practical baseline.
worked examples
example 1: quartzsite diesel setup (mild temps)
- heater setting: medium-low (2KW sufficient at 34°F)
- consumption: 0.09 gallons/hour
- overnight hours: 9
- diesel price: $3.10/gallon
calculation: 0.09 × 9 × $3.10 = $2.51/night
monthly cost: $2.51 × 30 = $75.30/month
example 2: caballo lake diesel setup (moderate temps)
- heater setting: medium (3.5KW at 28°F)
- consumption: 0.21 gallons/hour
- overnight hours: 10
- diesel price: $3.10/gallon
calculation: 0.21 × 10 × $3.10 = $6.51/night
monthly cost: $6.51 × 30 = $195.30/month
wait, that seems high for diesel. why?
because at 28°F running continuously at medium setting for 10 hours, diesel consumption adds up. the real advantage of diesel emerges when you compare it to propane at same conditions: propane at 28°F costs $7.56/night (example 2 above). diesel at same temp: $6.51/night. only 14% cheaper.
the big diesel savings come at extreme cold where propane consumption spikes but diesel consumption increases only modestly:
| temperature | propane cost/night | diesel cost/night | diesel savings |
|---|---|---|---|
| 44°F | $3.77 | $1.67 | 56% |
| 34°F | $5.75 | $2.51 | 56% |
| 28°F | $7.56 | $6.51 | 14% |
| 20°F | $10.44 | $8.37 | 20% |
| 10°F | $15.00 | $9.30 | 38% |
at mild temps (34-44°F), diesel is dramatically cheaper. at moderate temps (20-28°F), diesel heater at continuous medium is only modestly cheaper. at extreme cold (below 15°F), propane furnace fails to maintain temperature anyway, making diesel the only viable option regardless of cost.
four-month winter diesel cost estimates (35,000 BTU equivalent output, $3.10/gallon):
| location | avg overnight low | nightly cost | 4-month total |
|---|---|---|---|
| phoenix AZ | 44°F | $1.67 | $200 |
| quartzsite AZ | 34°F | $2.51 | $301 |
| big bend TX | 32°F | $2.79 | $335 |
| caballo lake NM | 28°F | $6.51 | $781 |
| cold snap (20°F) | 20°F | $8.37 | $1,004 |
electric heating cost calculator
when electric heat applies
electric heat only makes financial sense with shore power (rv park hookup). when boondocking, a 1,500W space heater drains a 200Ah battery in 96 minutes. not viable off-grid.
formula for shore power electric heat
nightly electric cost = heater wattage ÷ 1,000 × hours × price per kWh
example 1: rv park with metered electric (average rate)
- heater: 1,500W
- overnight hours: 8
- electricity rate: $0.167/kWh
calculation: 1,500 ÷ 1,000 × 8 × $0.167 = 1.5 × 8 × $0.167 = $2.00/night
monthly cost: $2.00 × 30 = $60/month
example 2: rv park with free electricity included
- nightly cost: $0.00
- monthly cost: $0.00 (but site fee likely $800-1,200/month)
electric heating is cheapest per BTU with shore power but the site fee eliminates any savings versus free boondocking with diesel heat.
complete winter fuel budget worksheet
total budget framework
heating is only one fuel cost. complete winter fuel budget includes:
| expense | typical monthly cost |
|---|---|
| propane for heat (35K BTU, 32°F avg) | $175-230 |
| propane for cooking | $30-45 |
| propane for hot water (if propane) | $25-40 |
| propane for refrigerator (if propane) | $40-60 |
| generator diesel (2 hours/day at 1 gallon/hour) | $180-200 |
| diesel heater fuel (if installed) | $45-75 |
| total typical fuel budget | $300-500/month |
note: if you have diesel heater instead of propane for heat, replace propane heating line with diesel heater line. if you have electric fridge and induction cooking, remove propane cooking and fridge lines.
the upgrade ROI calculator
question: does upgrading to diesel heat pay off for your trip?
formula: ROI days = diesel heater cost ÷ (propane nightly cost – diesel nightly cost)
example at quartzsite (34°F nights, 35K BTU furnace):
- propane nightly cost: $5.75
- diesel nightly cost: $2.51
- difference: $3.24/night
- diesel heater cost: $189
ROI calculation: $189 ÷ $3.24 = 58 days to break even
at 90-day winter season: saves $291 – $189 cost = $102 net profit first season. every season after: pure savings.
example at caballo lake (28°F nights):
- propane nightly cost: $7.56
- diesel nightly cost: $6.51
- difference: $1.05/night
- ROI: $189 ÷ $1.05 = 180 days to break even
verdict: diesel heater upgrade pays off fastest at mild-temperature locations (quartzsite, phoenix area). at colder locations, the savings per night are smaller because both fuels work hard. the real advantage of diesel at cold locations is maintaining temperature when propane furnaces fail.
rv skirting ROI calculator
formula: ROI days = skirting cost ÷ (unskirted nightly fuel cost × heat reduction percentage)
example: DIY skirting ($115) at quartzsite with propane heat:
- unskirted cost: $5.75/night
- heat reduction with skirting: 30%
- nightly savings: $5.75 × 0.30 = $1.73/night
- ROI: $115 ÷ $1.73 = 66 days
example: airskirt ($695) at quartzsite with diesel heat:
- unskirted cost: $2.51/night
- heat reduction: 37%
- nightly savings: $2.51 × 0.37 = $0.93/night
- ROI: $695 ÷ $0.93 = 747 days (2 seasons)
DIY skirting pays back in one season at any location. airskirt takes two seasons to pay back when already using diesel heat. for detailed skirting installation, see our [how to install rv skirting guide].
real cost comparison: my three winters
| winter | location | heating system | monthly heat cost | 4-month total |
|---|---|---|---|---|
| 2022-23 | quartzsite | propane only | $153 | $612 |
| 2023-24 | quartzsite + NM | propane + DIY skirt | $118 | $472 |
| 2024-25 | quartzsite + NM | diesel + skirting | $52 | $208 |
total savings from upgrading heating system over three winters: $404 first winter improvement, $264 second improvement. both upgrades paid back within the same season they were installed.
the numbers are clear. the calculator doesn’t lie. running propane furnace through an arizona winter without skirting costs $600+ in heat alone. the same winter with diesel heater and DIY skirting costs under $210. same comfort level, $400 difference, $304 in combined upgrade costs recovered in the first season.
run your numbers with the formulas above before your first trip. budget realistically. the math is straightforward: your furnace BTU rating, your destination overnight lows, current fuel prices. if the diesel heater ROI shows break-even under 90 days, buy it before you leave. if DIY skirting ROI is under one season, build it before you arrive. every dollar saved on heat is a dollar that extends your time on the road.