RV Calculators & Planning Tools

Practical calculators for RV power, towing, trip planning, water use, and campground costs. Built to help you work from your own numbers instead of somebody else’s setup.

Start With the Numbers That Matter

RV decisions get easier when the math is visible. These tools are built around the questions that actually come up when choosing equipment, planning a trip, or figuring out how long a system can run.

Electrical & Power

RV Daily Energy Use Calculator

Add up your 12V DC and 120V AC appliances to estimate total battery energy use per day. Use this result as the starting point for battery runtime, charging, solar, and power-station sizing.

Used to convert total daily energy into equivalent battery amp-hours.
Applied only to 120V AC loads.

Appliances and Loads

Estimated total battery energy use 0 Wh/day 0 Ah/day at 12.8 V
  • 12V DC appliance energy0 Wh/day
  • 120V AC appliance energy0 Wh/day
  • Inverter losses0 Wh/day
  • Battery-side AC energy0 Wh/day
  • Total battery-side energy0 Wh/day
For each appliance, enter how much power it uses, how many hours per day it runs, quantity, and duty cycle. Duty cycle is useful for loads such as refrigerators, water pumps, and furnace blowers that do not run continuously. For 12V DC devices, you can enter either watts or amps; for 120V AC devices, you can do the same.

RV Battery Bank Sizing Calculator

Work backward from your daily energy use to estimate the battery bank needed for the number of days you want to camp without recharging.

Use the total battery-side Wh/day from the Daily Energy Use Calculator above.
How long you want the battery bank to carry the load by itself.
This sets a starting usable-capacity percentage. You can change it below.
How much of the nominal battery capacity you plan to use.
Adds headroom for weather, heavier-than-expected use, aging, and ordinary real-world slop.
Used to convert the required energy into amp-hours.
Optional planning size for estimating the number of batteries needed.
Recommended nominal battery bank 521 Ah about 6,667 Wh at 12.8 V
  • Energy needed for selected days5,000 Wh
  • With reserve margin6,000 Wh
  • Required nominal capacity6,667 Wh
  • Required bank capacity521 Ah
  • Selected battery size2 × 300 Ah
  • Installed nominal capacity600 Ah / 7,680 Wh
This is a planning estimate, not a wiring diagram. Battery configuration, BMS limits, current draw, temperature, battery aging, cable size, series/parallel layout, and manufacturer requirements still matter. The battery-count estimate assumes each battery is already suitable for the selected bank voltage.

RV Battery Runtime Calculator

Estimate how long a battery bank can support a steady load. DC and AC loads are handled separately so inverter losses only appear when they actually belong there.

This only sets a starting usable-capacity percentage. You can change it below.
Use the bank's nominal voltage.
Total amp-hours for the full bank.
Your chosen usable portion of the battery bank.
AC loads include inverter losses.
Use average running wattage, not only the nameplate maximum.
Optional. Add inverter idle draw or another steady load drawn directly from the battery bank.
Estimated battery runtime 20.5 hours about 0.9 days at a continuous load
  • Nominal battery energy2,560 Wh
  • Usable battery energy2,048 Wh
  • Battery-side appliance draw100 W
  • Total battery-side draw100 W
This is a planning estimate, not fake precision. Temperature, battery age, BMS cutoff, wiring losses, inverter behavior, compressor cycling, and other real-world conditions can change actual runtime. Lead-acid batteries can also deliver less usable capacity at high discharge rates because of the Peukert effect.

RV Battery Charging Time Calculator

Estimate how long it takes to move a battery bank from its current state of charge to a target level while accounting for charger output, charging efficiency, and RV loads that keep running during charging.

The preset changes the default charging-efficiency assumption. You can edit it below.
Use the bank's nominal voltage.
Total amp-hours for the full bank.
Estimated battery state of charge before charging.
The level you want to reach.
The source label is for planning context. The actual calculation uses the charger output you enter.
Use expected DC output available to the RV battery bus.
95% is the LiFePO₄ planning default; lead-acid/AGM starts at 85%.
Optional. Include steady loads that are using charger output instead of charging the battery.
Estimated charging time 3.0 hours 20% → 90% state of charge
  • Battery energy to restore1,792 Wh
  • Gross charger output512 W
  • RV load while charging0 W
  • Net charging power512 W
  • Effective stored power486 W
LiFePO₄ batteries usually accept close to full charger output through most of the charge cycle, but the charger or BMS may reduce current near full charge. This is a planning estimate, not a promise to the minute.

RV Solar Harvest Calculator

Estimate how much energy an RV solar array may produce in a day using array size, peak sun hours, system efficiency, and shading losses.

Total rated wattage of all panels connected to the system.
Peak sun hours are equivalent full-sun hours, not total daylight hours.
Accounts for controller, wiring, panel temperature, angle, and other normal system losses.
Optional extra loss for trees, vents, antennas, partial shade, or poor exposure.
Used only to estimate equivalent amp-hours returned to the battery bank.
Optional. Enter your estimated daily consumption to see solar coverage or shortfall.
Estimated daily solar harvest 1,440 Wh about 1.44 kWh per day
  • Gross panel production1,800 Wh
  • After system losses1,440 Wh
  • After shading losses1,440 Wh
  • Equivalent battery charge113 Ah/day
This is a planning estimate. Weather, season, latitude, roof angle, panel temperature, shading, controller behavior, and battery state can all change actual harvest. Peak sun hours should come from a reasonable seasonal estimate for the area you expect to camp in.

RV Solar Array Sizing Calculator

Estimate how much solar panel capacity you need to replace your average daily RV energy use under realistic sunlight and system-loss assumptions.

Use the total battery-side Wh/day from the Daily Energy Use Calculator above.
Peak sun hours are equivalent full-sun hours, not total daylight hours.
Accounts for controller, wiring, panel temperature, angle, and other normal losses.
Optional additional loss for trees, roof equipment, partial shade, or poor exposure.
Adds headroom for variable weather, seasonal changes, and heavier-than-expected use.
Used to estimate how many panels are needed.
Recommended solar array 834 W about 5 × 200 W panels
  • Daily energy target2,500 Wh
  • Target with sizing margin3,000 Wh
  • Effective sun after shade4.5 h
  • Required rated array834 W
  • Selected panel count5 panels
  • Installed array size1,000 W
  • Estimated harvest at assumptions3,600 Wh/day
This is a planning estimate, not a promise from the sun. Weather, season, latitude, panel angle, roof layout, temperature, shading, controller limits, and battery charging conditions can all change actual production. Size the charge controller, wiring, fusing, and roof layout separately.

Trip & RV Planning

RV Campground Cost Comparison Calculator

Compare two campground options using the charges that actually affect the trip total, not just the advertised nightly rate.

The same stay length is used for both options.
Applied to the discounted site charges only. Adjust if local taxes work differently.

Campground A

Campground B

Campground A total $361.00
  • Discounted site charge$325.00
  • Taxes$26.00
  • Nightly add-ons$0.00
  • One-time costs$10.00
  • Effective nightly cost$72.20
Campground B total $375.80
  • Discounted site charge$260.00
  • Taxes$20.80
  • Nightly add-ons$40.00
  • One-time costs$15.00
  • Effective nightly cost$67.16
Enter the fees for both options to compare the real trip totals.

RV Trip Fuel Cost Calculator

Estimate towing fuel, local driving fuel, total gallons, and total fuel cost for an RV trip instead of budgeting from the highway miles alone.

Enter the towing distance to the destination. The trip type below handles the return leg.
Round trip doubles the towing distance automatically.
Use your real towing average when you have it.
Use an expected trip average if prices vary along the route.
Optional driving after the camper is set up, including sightseeing and errands.
Your expected MPG for local driving without the trailer.
Used only to show average fuel cost per trip day.
Optional cushion for traffic, idling, detours, terrain, or worse-than-expected mileage.
Estimated trip fuel budget $240 575 total miles
  • Towing miles500 mi
  • Towing fuel55.6 gal
  • Towing fuel cost$194.44
  • Local fuel5.4 gal
  • Local fuel cost$18.75
  • Base trip fuel cost$213.19
  • Budget with buffer$234.51
  • Average fuel cost per day$58.63
  • Average fuel cost per mile$0.41
This is a budgeting estimate. Wind, grade, speed, traffic, idling, generator fuel, tire pressure, vehicle load, and fuel-price changes can all move the real number. If your truck uses a different fuel while towing than during local driving, calculate those legs separately.

RV Freshwater Usage Calculator

Estimate how long your freshwater tank may last based on the people aboard, showers, drinking and cooking, dishes, toilet use, and other daily water needs.

Use your RV's usable freshwater tank capacity.
Used for per-person drinking, cooking, shower, and toilet estimates.
Water you prefer not to plan on using, for pump pickup limits or a safety cushion.
Include coffee, drinking water, and water used in food preparation.
Showers
For example, 0.5 means one shower every two days per person.
Count actual water-on time, not total time standing in the shower.
RV shower heads often use less than household fixtures. Use your measured rate when known.
Other Daily Use
Total daily water used for dishes and basic kitchen cleanup.
Only include this if your toilet uses the freshwater system.
A planning estimate. Actual RV toilet use varies with how long the pedal or valve is held.
Include brushing teeth, handwashing, pet water, cleaning, and other small uses.
Estimated freshwater duration 4.1 days about 11.0 gallons per day
  • Usable tank water45.0 gal
  • Drinking & cooking2.0 gal/day
  • Showers4.5 gal/day
  • Dishwashing2.5 gal/day
  • Toilet use1.5 gal/day
  • Handwashing & other2.0 gal/day
  • Total freshwater use12.5 gal/day
  • Daily use per person6.3 gal
This is a planning estimate. Real use changes quickly with shower habits, dishwashing style, toilet use, leaks, pets, outdoor rinsing, and how completely the tank can actually be drawn down. If you refill from jugs or campground water during the trip, treat those gallons as additional supply rather than changing the tank size.

RV Payload & Towing Worksheet

Check how passengers, cargo, hitch hardware, and trailer pin or tongue weight affect the truck's payload, then compare entered trailer and combined weights with the ratings you provide.

Truck Ratings & Load
Use the payload number from the truck's Tire and Loading Information label.
Optional. Use the rating that applies to your exact truck configuration.
Optional gross combined weight rating for truck and trailer together.
Optional scale weight with people, cargo, fuel, and hitch installed, but trailer disconnected.
Total actual weight of everyone riding in the truck.
Tools, coolers, bed cargo, aftermarket equipment, and other added weight.
Fifth-wheel hitch, weight-distribution hardware, or other hitch equipment carried by the truck.
Trailer
Best input is an actual loaded scale weight. Otherwise use a realistic loaded estimate.
Measured is better. Percentage is a planning estimate only.
Fifth wheels often use a larger percentage than travel trailers. Use your own known value when possible.
Remaining payload after trailer load 200 lb about 93% of payload used
  • Passengers + cargo + hitch800 lb
  • Available payload before pin/tongue2,200 lb
  • Estimated / entered pin-tongue weight2,000 lb
  • Total payload used2,800 lb
  • Payload remaining200 lb
  • Trailer vs tow rating10,000 / 15,000 lb
  • Estimated combined weightNot calculated
  • Combined vs GCWRNot calculated
This worksheet only compares the ratings and weights you enter. It does not verify axle ratings, tire ratings, receiver or hitch ratings, braking requirements, weight distribution, or manufacturer-specific towing limits.

Useful Estimates, Not Fake Precision

Every calculator will show the assumptions behind the result. Real RV systems are affected by temperature, equipment efficiency, battery condition, wiring losses, driving conditions, and how people actually use the camper.