What to Bring on a Day Hike: The Complete Packing Checklist

Water: how much to carry

The rule of thumb is half a liter per hour of moderate activity in mild temperatures. Double that in heat or above 8,000 feet. For a typical 4-hour hike that's 2 liters per person; for a strenuous summer summit, plan for 3 to 4 liters.

• Reservoir (2–3 L bladder): easy sipping while moving keeps you ahead of dehydration.
• Backup bottle (500 mL): if the bladder fails or freezes, you still have water.
• Electrolyte tabs or mix: plain water alone causes cramping on long, hot days.
• Water filter or purification tabs: mandatory if any segment of your hike crosses a stream or lake.

Food: calories per hour

Plan on roughly 200–300 calories per hour of hiking. Skip anything that melts (chocolate in summer), freezes solid (energy bars in winter), or crushes (chips). Mix fast carbs with fat and protein so you don't bonk two hours from the car.

• Trail mix with nuts, dried fruit, and M&Ms (heat-tolerant chocolate)
• Tortilla wraps with peanut butter and honey — they don't crush
• Salty snacks: jerky, salted nuts, pretzels — replace what you sweat out
• One emergency bar above your planned consumption, untouched, every hike

Layering for any forecast

Cotton kills — it holds water, stops insulating, and chills you fast. Build your kit around merino wool or synthetic fabrics, and bring more layers than you think you'll need above 6,000 feet.

• Base layer: moisture-wicking tee or long-sleeve.
• Insulating mid-layer: fleece or light puffy, always in the pack even in July.
• Wind/rain shell: a 6-ounce packable jacket. Mountain weather flips in 30 minutes.
• Hat + gloves: light beanie and liner gloves cost ounces and save days above treeline.
• Sun hat or cap: wide-brim for desert, ball cap for forest.

Navigation

• Phone with offline maps downloaded (Gaia GPS, CalTopo, or AllTrails Pro) — cell service vanishes within minutes of most trailheads.
• Paper map and compass for any hike longer than 5 miles or with unmarked junctions.
• Backup battery pack — GPS chews through a phone battery on a long day.

First aid and emergency

• Compact first-aid kit with blister care (the #1 trail injury), athletic tape, ibuprofen, antihistamine.
• Headlamp + spare batteries, even on a 2-hour hike. Getting turned around past sunset is the most common reason hikers need rescue.
• Emergency space blanket and a small fire kit (lighter + cotton balls in petroleum jelly).
• Multi-tool or knife.
• Whistle (three short blasts = international distress signal).
• Satellite communicator (Garmin inReach Mini, ZOLEO) for any remote or solo trip.

Sun and skin protection

• SPF 30+ sunscreen, reapplied every 2 hours. UV intensity doubles every 3,000 feet of elevation.
• SPF lip balm — your lips burn first and last.
• Polarized sunglasses, mandatory on snow or open rock.
• Bug spray with DEET or picaridin May through September east of the Rockies.

Footwear and footcare

The single best upgrade for new hikers isn't boots — it's merino wool socks. They wick sweat, resist odor, and dramatically reduce blisters.

• Trail runners for most terrain under 10 miles; light boots for rocky ankle-twisting trails.
• Two pairs of socks: one on, one in the pack. Changing socks at the halfway point feels like a small miracle.
• Pre-tape known hot spots with leukotape before they blister.
• Gaiters in scree, sand, or snow.

The small things most people forget

• Trash bag (pack out everything, including biodegradable food scraps).
• Ziplock bags for used toilet paper — pack it out, do not bury.
• Hand sanitizer.
• Trekking poles for any descent over 1,500 feet — they save your knees.
• Cash for trailhead fees that don't take cards.
• A printed trip plan left with someone at home, with your expected return time.