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Plastic Footprint Calculator

Count the bottles, bags, cups and takeout boxes you use in a typical week. See how many you go through in a year and what they weigh, and which two or three swaps would cut the most.

A typical week

Items per week

Enter how many of each you use in an ordinary week, at home, at work and eating out. The numbers to start with are only an example.

Your year of single-use plastic

How the numbers are worked out

Each count is multiplied by 52 weeks and by a typical weight for that item, taken from life-cycle studies and industry data. Real items vary: a thin store bag can weigh 5 grams and a thick one over 30, and lightweight water bottles keep getting lighter. So treat the total as a good estimate, not a weigh-in.

ItemPlasticSource
Water bottle, 500 mL with cap and label9.3 g[1]
Soda bottle, 500 mL with cap and label25 g[1]
Grocery carrier bag, HDPE8.1 g[2]
Produce bag, HDPE roll bag2.5 g[3]
Takeout container, rigid polypropylene, 670 mL31.5 g[4]
Foam takeout box, polystyrene, 670 mL7.8 g[4]
Hot cup: plastic lining 1 g plus lid 3.2 g4.2 g[5]
Cold drink cup, 650 mL (PP 15 g, PET 19 g)17 g[5]
Straw, polypropylene0.5 g[6]
Cutlery, one meal's worth, polystyrene11.8 g[7]

Paper coffee cups count because they are lined with a thin layer of polyethylene to keep them from leaking. The produce bag figure is our estimate: a 12 by 17 inch roll bag that is 10 to 14 microns thick weighs about 2.5 to 3.5 grams.

Why weight matters more than count

A takeout container weighs as much as 60 straws, so one lunch a week outweighs a daily straw habit several times over. That is why the swaps are ranked by weight. Straws still matter to wildlife, but bottles, bags and food containers are where most people's plastic is.

Reusables only pay off if you use them. A UK Environment Agency study found that a non-woven polypropylene bag has to be used 11 times, and a cotton bag 131 times, before its climate impact drops below that of a single-use bag used once. Those figures ignore litter, which is the main reason bag bans exist, so they understate the case for reusables near the coast.

Where the world's plastic goes

The OECD's Global Plastics Outlook estimates the world threw away 353 million tonnes of plastic in 2019. Only 9% was recycled; 19% was incinerated and almost 50% went to sanitary landfill. The remaining 22% was dumped, burned in the open or leaked into the environment, and 6.1 million tonnes leaked into rivers, lakes and the sea, with about 1.7 million tonnes reaching the ocean that year. Where your own plastic ends up depends on how it is collected where you live, so this tool doesn't turn your total into an ocean number.

For scale, a 2020 study in Science Advances put total US plastic waste in 2016 at 42 million tonnes, about 130 kg (287 lb) per person, counting everything from packaging to furniture. The items here are a small, easy-to-change slice of that. For more ideas, see ways to reduce plastic waste in the ocean and cutting plastic on a boat trip.

Sources

  1. IBWA / Trayak, LCA of Drinking Water Packaging (2021): 500 mL water bottle 8.30 g + cap 0.77 g + label 0.25 g; 500 mL soda bottle 22.22 g + 2.52 g + 0.41 g. bottledwater.org
  2. UK Environment Agency, Life cycle assessment of supermarket carrier bags (2011): HDPE bag 8.12 g; reuse needed by other bags. assets.publishing.service.gov.uk
  3. US Poly Pack, 12 × 17 in HDPE produce bags, 14 microns (thickness used for our estimate). uspolypack.com
  4. UNEP Life Cycle Initiative, Single-use take-away food containers (2020), citing Gallego-Schmid et al. 2019: PP 31.5 g, extruded polystyrene 7.8 g. www.lifecycleinitiative.org
  5. UNEP Life Cycle Initiative, Single-use beverage cups (2021): 355 mL paper cup PE liner 1 g, PS lid 3.2 g; 650 mL cups PP 15 g, PET 19 g. www.lifecycleinitiative.org
  6. Polymers (2025), life-cycle assessment of straws for Greece: PP straw 0.5 g. pmc.ncbi.nlm.nih.gov
  7. UNEP Life Cycle Initiative, Single-use tableware (2021), citing Razza et al. 2009: 11.8 kg of polystyrene cutlery per 1,000 meals. www.lifecycleinitiative.org
  8. OECD, Global Plastics Outlook: Policy Highlights (2022). www.oecd.org
  9. Law et al., "The United States' contribution of plastic waste to land and ocean", Science Advances (2020). pmc.ncbi.nlm.nih.gov

Questions

How much plastic is in a water bottle?

About 9.3 grams for a typical 500 mL (16.9 oz) bottle with its cap and label, based on an industry life-cycle study of seven brands. Soda bottles need thicker walls to hold the fizz, so a 500 mL soda bottle is closer to 25 grams.

Are paper coffee cups plastic-free?

No. They are lined with polyethylene so they don't leak, about 1 gram in a 12 oz cup, and most come with a 3 gram plastic lid.

Is a reusable bag really better?

Only if you keep using it. On climate impact alone, a polypropylene bag beats single-use bags after about 11 uses and a cotton tote after about 131, according to the UK Environment Agency. Keep the ones you already own and use them for years.

Why doesn't it tell me how much of my plastic ends up in the ocean?

Because that depends on where you live, not on how much you use. Globally, the OECD estimates 22% of plastic waste is mismanaged and about 1.7 million tonnes reached the ocean in 2019, but in places with good collection your share is far smaller. Any personal ocean figure would be a guess.

Is my data stored?

Your counts are saved only in your own browser, so they are there next time. Nothing is sent to Lazy Seas, and the share text is only copied if you press the button.