Leave No Trace Calculator
Waste and impact minimization from group size and duration.
About this calculator
This calculator estimates the practical waste and disposal logistics behind a Leave No Trace camping trip, built around the seven principles published by the Leave No Trace Center for Outdoor Ethics. Trash generation scales with your chosen camp style — ultralight/LNT-focused trips generate the least per person per day, standard backpacking more, and car camping considerably more — multiplied by group size and trip length. Human waste is estimated at one bowel movement per person per day, which sets both the number of 6–8 inch cat holes needed (dug at least 200 feet from water, camp, and trails, per the Leave No Trace Center's published guidance) and, as an alternative for above-treeline or otherwise sensitive terrain, the number of WAG (waste-alone-gel) pack-out bags. Gray water from cooking and washing is similarly scaled by camp type and group size, and the Leave No Trace Center's principles likewise call for carrying it at least 200 feet from water sources before scattering it.
Campfire impact — wood consumed and scorch-scar area — depends on whether you choose no fire, a small fire, or a large one, each with different assumed burn hours and wood consumption per day. All of this rolls up into a single 0–100 impact score built additively from group size, camp type, fire use, proximity to water (camping closer than 200 feet from a water source adds a penalty), and trip duration, then bucketed into a Minimal/Low/Moderate/High rating. The per-person daily rates are practical planning averages, but the 200-foot water threshold itself is drawn directly from the Leave No Trace Center for Outdoor Ethics' published Seven Principles — still, actual impact varies by ecosystem sensitivity, group behavior, and how carefully waste is actually packed out or buried, so use the score as a planning nudge rather than a precise environmental measurement.
Inputs
Results
Impact score (0–100)
39
Figures current as of 1999. Source: Leave No Trace Center for Outdoor Ethics, "Leave No Trace Seven Principles" (reproduced by the U.S. National Park Service)
How to Use This Calculator
- Enter group size and trip duration (days), then choose a camp type: ultralight/LNT-focused, standard backpacking, or car camping.
- Select your fire use level (no fire, small campfire, or large campfire) and enter the camp-to-water distance in feet.
- Read the LNT impact score (0–100, lower is better) and impact rating (Minimal, Low, Moderate, or High).
- Review the estimated total trash, cat holes and WAG bags needed, gray water volume, and firewood/fire scar estimates.
- Use these results to plan trip logistics that minimize impact, such as packing out more waste or reducing fire use.
How the result changes with Trip duration (days)
| Trip duration (days) | Impact score (0–100) |
|---|---|
| 1.5 | 36 |
| 2.25 | 38 |
| 4.5 | 42 |
| 7.5 | 48 |
What each input means
- Group size
- Number of people in your camping group.
- Trip duration (days)
- Number of days/nights on the trip.
- Camp Type
- Camping style affects environmental impact.
- Fire Use
- Campfire usage level.
- Camp-to-water (ft)
- Distance from camp to nearest water source. LNT recommends 200+ ft.
What each result means
- Impact score (0–100)
- Environmental impact score. Lower is better. Under 20 = Minimal impact.
- Impact rating
- 1 = Minimal, 2 = Low, 3 = Moderate, 4 = High impact.
- Total trash (lb)
- Estimated pack-it-out trash weight for the trip.
- Cat holes needed
- Number of 6–8" deep cat holes needed (200+ ft from water).
- WAG bags needed
- Pack-out waste bags if above treeline or in sensitive areas.
- Gray water (gal)
- Cooking/washing water to scatter 200+ ft from water sources.
- Firewood needed (lb)
- Estimated firewood consumption. Use only dead and downed wood.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersGroup size = 4, Trip duration (days) = 3, Camp Type = 2, Fire Use = 1 = 5 input(s) provided
- Calculate Impact scoreImpact score39 = 39
- Calculate Impact ratingImpact rating2 = 2
- Calculate Total trashTotal trash = dailyTrashLb * tripDays6 = 6
Figures and sources
- Leave No Trace Seven Principles — 200-foot distance for camps, human waste disposal, and dishwater from water sources (1999) — Leave No Trace Center for Outdoor Ethics, "Leave No Trace Seven Principles" (reproduced by the U.S. National Park Service)
Engine last updated . Checked against 3 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why does car camping generate three times as much trash as ultralight camping in this calculator?
The trash-generation rate is looked up by camp type — 0.3 lb per person per day for ultralight/LNT-focused trips versus 1.5 lb per person per day for car camping, a 5x difference reflecting how car camping typically involves more packaged food, disposable supplies, and general convenience items that ultralight backpackers deliberately avoid to keep pack weight and waste down.
How does the calculator decide how many cat holes or WAG bags I'll need?
Both are estimated at one bowel movement per person per day, so the cat-hole count and WAG-bag count both equal group size times trip days. Cat holes (6-8 inches deep, dug 200+ feet from water) are the standard LNT method; WAG bags are presented as the pack-out alternative for above-treeline or otherwise sensitive terrain where digging isn't appropriate.
Why does camping closer than 200 feet from water increase my impact score?
The Leave No Trace Center for Outdoor Ethics' published Seven Principles set 200 feet as the minimum distance from water sources for camps, waste disposal, and gray water dispersal, so the calculator adds a penalty equal to (200 minus your entered distance) divided by 10 whenever you're closer than that threshold — meaning camping right at the water's edge adds a meaningfully larger penalty than camping just inside the 200-foot line.
What goes into the overall 0-100 Impact Score?
It's an additive score built from five factors: group size (up to 20 points), camp type (0 to 30 points), fire use (0, 10, or 20 points for none/small/large fires), a proximity-to-water penalty if you're closer than 200 feet, and trip duration (up to 15 points), capped at 100 total. It's then bucketed into Minimal, Low, Moderate, or High as a quick, relative gauge of your trip's footprint rather than an absolute environmental measurement.
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