Originally posted on 11th Oct 2024

The trash bag is too small. Again. You're stretching plastic that won't stretch, watching it snap back or—worse—tear at the corner. Sound familiar? Here's exactly how to determine what size your trash can is in under 2 minutes: check for a manufacturer's label on the bottom or inside rim, measure and calculate using our simple formulas, or match your can's dimensions to our reference charts below.

Every wrong-sized bag costs you twice—once at the register, once in frustration. While incorrect trash bags create daily annoyance when bags slip down, won't fit, or tear during removal, the financial impact extends beyond the purchase price. According to EPA research, the average household wastes $728 per person annually on food waste alone, making proper waste management essential. This guide delivers three foolproof measurement methods that work for any trash can, from that unlabeled kitchen bin you inherited to the mystery-sized office receptacle that's been defeating you for months.

Key Takeaways

• Find your trash can size in 3 ways: Check manufacturer labels (30 seconds), measure and calculate (90 seconds), or perform the water test (5 minutes).
• Convert measurements easily: Multiply liters by 0.264 for gallons, divide cubic inches by 231 for gallons.
• Use the +2 gallon rule: Buy bags labeled 2-3 gallons larger than your can's actual capacity for proper overhang.
• Match size to household: 10-13 gallons for 1-2 people, 20-30 gallons for 3-4 people, 30-40 gallons for 5+ people.
• Standard room sizes: Bathrooms need 4-7 gallons, kitchens 10-40 gallons, outdoor bins typically 64-96 gallons.
• Prevent common problems: Bags slipping means you need larger bags; tearing indicates overfilling or undersized bags.

Understanding Trash Can Sizing

Think of your trash can like a swimming pool—we measure it by how much it holds, not how tall it stands. That volume, measured in gallons, determines everything from which bags to buy to how often you'll haul it to the curb. The key difference is that manufacturers typically measure to the theoretical brim, while you need to know the practical capacity—where you'd actually tie off a bag without performing gymnastics.

Standard Trash Can Capacities by Room and Use

Here's what's in your home or establishment right now, measured and mapped:

Room/Location	Typical Size Range	Common Dimensions (H×W×D)	Best Bag Size	Household Size Recommendation
Bathroom	4-7 gallons	12-14" × 10-11" × 8-9"	6-8 gallon bags	All households
Bedroom/Office	7-10 gallons	14-16" × 11-12" × 10"	10-13 gallon bags	1-2 person spaces
Kitchen (Small)	10-13 gallons	17-20" × 11-13" × 10-11"	13 gallon bags	1-2 person households
Kitchen (Medium)	20-30 gallons	24-28" × 15-18" × 12-14"	30-33 gallon bags	3-4 person households
Kitchen (Large)	30-40 gallons	28-32" × 18-20" × 14-16"	39-45 gallon bags	5+ person households
Garage/Utility	30-45 gallons	32-36" × 20-24" × 16-18"	45-55 gallon bags	All households
Outdoor/Curbside	64-96 gallons	42-48" × 28-32" × 24-28"	95-96 gallon bags	Municipal standard
Commercial	32-64 gallons	36-42" × 20-28" × 18-24"	55-65 gallon bags	Office/retail spaces

Armed with these benchmarks, let's identify your specific can's size using whichever method works best for your situation.

3 Simple Methods to Determine Your Trash Can Size

You've got three reliable options. Pick the one that matches your situation—they all lead to the same answer in under 2 minutes.

Method 1: Check for the Manufacturer's Label (30 Seconds)

Start here—it's the fastest route to certainty. Most trash cans have capacity labels in predictable spots, waiting to solve your problem instantly.

Common search locations:

1. Flip it over: Empty can, turn it upside down. The bottom center often features molded numbers like "13 GAL" or "50L"—jackpot found in under 5 seconds.
   
   
2. Feel the rim: Run your fingers along the inside top edge. Many manufacturers embed raised numbers here, especially on commercial trash cans—you'll know when you find it.
   
   
3. Check the back: Pedal cans and decorative bins often sport labels on the rear exterior, about one-third up from the bottom.
   
   
4. Peek inside the base: Some brands stick labels on interior walls near the bottom, particularly heavy-duty trash cans.
   
   

Decode what you find:

• "13 GAL" = You're done, that's your size
• "50L" = Multiply by 0.264 to get gallons (50L = 13.2 gallons)
• "52 QT" = Divide by 4 (52 quarts = 13 gallons)

The 10-second future-proof move: Snap a photo of that label. Save it to your phone's favorites. Never guess in the trash bag aisle again.

Method 2: Measure and Calculate (90 Seconds)

No label? No problem. Your tape measure plus your phone's calculator app equals exact answers in 90 seconds. This method turns any trash can into a simple geometry problem you already know how to solve.

For Rectangular/Square Cans:

Grab that tape measure and follow this exact sequence:

1. Height first: Base to rim (ignore the lid). Let's say you get 20 inches.
   
   
2. Width next: The widest point of the opening. You measure 15 inches.
   
   
3. Depth last: Front to back at the same level. You find 10 inches.
   
   
4. Multiply: 20 × 15 × 10 = 3,000 cubic inches
   
   
5. Divide by 231: 3,000 ÷ 231 = 12.99 gallons
   
   

Your result: That's a 13-gallon can. Buy 13-gallon bags and they'll fit perfectly with proper overhang.

For Round/Cylindrical Cans:

The circle formula from eighth grade finally becomes useful:

1. Height: Measure base to rim. Say it's 24 inches.
   
   
2. Diameter: Straight across the opening's center. You get 14 inches.
   
   
3. Find radius: 14 ÷ 2 = 7 inches
   
   
4. Calculate: 3.14159 × 7² × 24 = 3,694 cubic inches
   
   
5. Convert: 3,694 ÷ 231 = 15.99 gallons
   
   

Your result: A 16-gallon can. Get 20-gallon bags for the right fit.

This garbage can capacity calculator approach works for any shape—oval cans just need averaged width measurements.

Method 3: The Water Test (5 Minutes)

That decorative can with curves in all the wrong places? The one that defeated your tape measure? Water never lies about volume. This old-school method takes 5 minutes and delivers laboratory-grade accuracy.

Before you start: This works best for cans under 20 gallons. Bigger than that becomes a workout.

Your equipment:

• A clean gallon milk jug or pitcher (your measuring tool)
• Water source (kitchen sink or hose)
• Towels (trust us on this)

The process:

1. Fill by the gallon: One jug at a time, keeping count on your fingers or phone.
   
   
2. Stop at reality: Fill only to where you'd tie a bag (about 3-4 inches from top).
   
   
3. Count your gallons: Seven gallons poured? You've got a 7-gallon can.
   
   
4. Round up smart: 10.5 gallons measured means buy 13-gallon bags.
   
   

Your measurements → The bags you need:

• Measured 3.5-4.5 gallons → Buy 6-gallon bags
• Measured 10-12 gallons → Buy 13-gallon bags
• Measured 18-22 gallons → Buy 30-gallon bags
• Measured 28-32 gallons → Buy 33-39 gallon bags

Matching Your Trash Can to the Right Bag Size

You might assume a "13-gallon" trash bag fits a 13-gallon can perfectly. Here's the truth: that intentional mismatch on the label prevents the three curses of trash duty—the bag that slips into the can, the bag that tears when you lift it, and the bag that simply won't fit.

Understanding the "+2 Gallon Rule"

Picture pulling a fitted sheet over a mattress—you need extra material to grip the corners. Trash bags work identically. That "extra" capacity on the label isn't false advertising; it's the overhang that keeps your bag in place.

The engineering is simple according to industry sizing standards:

• 3-6 inches of overhang: Grips the rim and stays put
• Gathering room at top: Space to twist and tie without tearing
• Lift clearance: Extra material prevents bottom blowouts

Common Bag Sizes Reference Chart

Stop second-guessing at the store. Here's exactly what label to look for based on your can's actual capacity:

Bag Label Says	Your Can Actually Is	Where It Lives	Bag Dimensions	Perfect For
4-6 gallon	3-5 gallon cans	Small wastebaskets	17" × 18"	Bathroom trash cans, desk bins
8-10 gallon	7-8 gallon cans	Medium bins	22" × 22"	Bedrooms, home offices
13 gallon	10-12 gallon cans	Standard kitchen	24" × 27"	Most kitchen trash cans
20-30 gallon	20-27 gallon cans	Large kitchen	30" × 33"	Family kitchens, break rooms
33 gallon	28-32 gallon cans	Outdoor/garage	33" × 39"	Commercial garbage cans
39-45 gallon	35-40 gallon cans	Heavy duty	33" × 46"	Garages, workshops
55-60 gallon	45-55 gallon drums	Industrial	38" × 58"	Industrial trash cans

The eternal question—13 gallon vs 30 gallon trash can—has a simple answer: Count your people. One or two? Stick with 13-gallon. Three or more? Graduate to 30-gallon. The difference is emptying twice weekly versus once.

Match Thickness to Task

Bag thickness (measured in mils) determines what abuse your bag can handle. Industry standards range from 0.7 to 4.0 mils, with standard kitchen bags around 0.9 mil and contractor-grade starting at 3.0 mil:

• 0.7-0.9 mil: Paper, tissues, dry office waste
• 1.0-1.2 mil: Standard kitchen duty including food scraps
• 1.5-2.0 mil: Wet waste, outdoor use, anything with edges
• 3.0+ mil: Construction debris, yard waste, things that puncture

Choosing the Right Size Trash Can for Your Space

The perfect trash can size matches your actual waste rhythm, not just what fits in the corner. Too small means constant emptying. Too large means science experiments growing at the bottom. Understanding what size your trash can should be starts with your household's daily habits.

Kitchen Trash Can Selection Guide

Your kitchen generates significant household waste—research shows food waste alone accounts for 40-50% of total household garbage. Get the size wrong and you'll feel it daily.

1-2 people: Go with 10-13 gallons. Large enough to skip a day, small enough to force regular emptying before odors develop. Standard kitchen trash cans in this range tuck under sinks or slide into corners without dominating the space.

3-4 people: The 20-30 gallon sweet spot. Handles a full day's cooking and cleanup without requiring Herculean strength to haul when full. Look for foot pedals—your hands are always full in the kitchen.

5+ people: Consider 30-40 gallons or dual-can systems. Large families generate waste faster than you'd think, especially with school lunches and snack packaging. Many opt for indoor trash cans with separate recycling compartments.

Bathroom and Bedroom Sizing

Small spaces need proportional solutions:

• Bathrooms: 4-7 gallons fits beside toilets, handles typical bathroom waste, empties weekly
• Bedrooms: 7-10 gallons manages tissues and personal items without overwhelming décor
• Home offices: 10-13 gallons swallows paper waste and coffee cups through a workweek

Outdoor and Garage Requirements

Weather and critters change the game outside:

• Curbside collection: Municipal standards typically require 64-96 gallon wheeled bins, with many municipalities offering multiple sizes from 16 to 96 gallons.
• Garage workspace: 32-45 gallons handles project waste without constant trips outside.
• Pool/patio: 23-32 gallons in weather-resistant materials, bonus points for locking lids.

Common Trash Can Sizing Problems and Solutions

Every trash can problem has a 2-minute fix. Here's how to solve the most common issues.

Problem: Bag Constantly Slips Down

You tie it tight. Five minutes later it's swimming at the bottom of the can.

The fix: Your bags are too small. If you're using 13-gallon bags, jump to 20-gallon—the extra material grips better. Can't upsize? Loop rubber bands around the rim over the bag edge. Works every time.

Problem: Can't Determine Size of Odd-Shaped Bins

That decorative can with the weird taper. The oval one from the designer store. Geometry fails you.

The fix: Water test wins here. Pour gallon by gallon, count as you go. For quick estimates, check how big is a standard trash can and compare visually.

Problem: Bags Tear When Removing

Every bag removal becomes a careful extraction operation. One wrong move and—rip.

The fix: You're either overfilling or undersizing. Bags should be 2-3 gallons larger than can capacity. Never fill past 85%. If you're doing both these things, increase bag thickness—jump from 1.0 to 1.5 mil.

Special Considerations for Different Spaces

Office and Commercial Settings

Managing waste at scale requires standardization. Stop buying six different bag sizes:

• Individual desks: 7-10 gallons (empties weekly)
• Break rooms: 23-32 gallons (daily emptying)
• Restrooms: 13-20 gallons (high turnover)
• Janitorial carts: 44-55 gallon mobile units

Invest in commercial garbage cans with hands-free operation. Your facilities team will thank you.

Multi-Unit Residential

Apartment dwellers face limited storage, shared disposal, and sometimes restrictive chute systems. The universal solution: 13-gallon kitchen can, 4-gallon bathroom bin, and a commitment to regular disposal. If your building has chute restrictions, verify maximum bag dimensions before bulk buying.

Quick Troubleshooting Guide

"My 13-gallon bags won't fit my kitchen can" — Your can is bigger than 13 gallons. Measure it (Method 2) and expect to find 15-20 gallons. Solution: Buy 30-gallon bags.

"The label says 50L but I don't know what that means" — 50 liters = 13.2 gallons. Standard 13-gallon bags will work perfectly.

"My can has no label and is weirdly shaped" — Water test time. Pour, count, done. Then check our garbage bag size chart for the right match.

"I need bags for five different-sized cans" Make a phone note: "Kitchen: 30gal, Bathroom: 6gal, Office: 13gal" etc. Buy your top two sizes in bulk, others as needed.

Making Your System Work Long-Term

You've measured. You know your sizes. Here's how to never think about this again:

1. Screenshot this: Can location + size (Kitchen: 13gal, Garage: 32gal)
2. Standardize what you can: Replace random bins with matching sizes
3. Buy ahead: 3-month supply of your two main sizes
4. Set a reminder: Phone alert for reordering before you run out

Need help understanding metric measurements? Our guides for garbage bag sizes in liters and garbage bag sizes in gallons translate everything.

Finding the right trash can size isn't about perfection—it's about ending the daily frustration of bags that don't fit, slip down, or tear at the worst possible moment. With the three methods outlined above, you now have everything needed to identify any trash can's size in under 2 minutes. Whether you check for a manufacturer's label, break out the tape measure, or conduct the foolproof water test, you'll never stand puzzled in the trash bag aisle again. The simple act of matching your can's actual capacity to the right bag size—remembering that +2 gallon rule—transforms a twice-daily wrestling match into something that just works. No more stretched plastic, no more waste, just the quiet satisfaction of a system that fits.

Take Action Now

Right now, while you're thinking about it—go measure your kitchen trash can. It's the one that causes the most frustration and the easiest win. Use Method 1 (check for a label) or Method 2 (tape measure and math). Write down the result. Take a photo. Save yourself from ever playing the guessing game in the trash bag aisle again.

Ready to upgrade from whatever mismatched system you're wrestling with? Browse our complete trash can collections for solutions that actually fit your space and life. Or jump straight to the deals—our current trash cans on sale include commercial-grade options at prices that make standardizing your entire system surprisingly affordable.