The average number of menstrual cycles is 12.6, based on 8 data points.
The average number of years a person menstruates is assumed to be 37.5 years. The NHS doesn’t explicitly say the number of years a person menstruates, but the data they report suggests a similar value.
Number of units
Single-use products
The average number of pads per cycle is 19.1, based on 6 data points.
The average number of tampons per cycle is 20.0, based on 4 data points.
The average number of single use items used in the modelling is 20.0 items per cycle – this is an average of 10 pads and 10 tampons.
Multiplied by 12.6 cycles per year (see Section 1), this equates to 253 items per year.
Multiplied by 10 years, this equates to 2,526 items per 10 years.
Multiplied by 37.5 years of menstruation per lifetime (see Section 1), this equates to 9,472 items per lifetime.
Cup
The average number of years per menstrual cup is 7.5, based on 13 data points.
This equates to 0.13 cups per year.
Multiplied by 10 years, this equates to 1.3 cups per 10 years.
Multiplied by 37.5 years of menstruation per lifetime (see Section 1), this equates to 5.0 cups per lifetime.
Reusable pads
The average number of reusable pads per year is 2.4, based on 3 data points.
Multiplied by 10 years, this equates to 24 reusable pads per 10 years.
Multiplied by 37.5 years of menstruation per lifetime (see Section 1), this equates to 90 reusable pads per lifetime.
Underwear
The average number of period underwear per year is 1.9, based on 5 data points.
Multiplied by 10 years, this equates to 19 underwear per 10 years.
Multiplied by 37.5 years of menstruation per lifetime (see Section 1), this equates to 69 underwear per lifetime.
Price
Single-use products
The average unit price per single-use pad is £0.16, based on 164 data points.
The average unit price per tampon is £0.13, based on 88 data points.
The average unit price per single-use item used in the modelling is £0.14.
Multiplying the number of units from Section 2 by this unit price gives:
- £38.57 per year (= £0.14 * 253 units per)
- £385.71 per 10 years (= £0.14 * 2,526 units)
- £1,446.40 per lifetime (= £0.14 * 9,472 units)
Cup
The average unit price per cup is £25.47, based on 12 data points.
Multiplying the number of units from Section 2 by this unit price gives:
- £3.40 per year (= £25.47 * 0.13 units)
- £33.96 per 10 years (= £25.47 * 1.3 units)
- £127.35 per lifetime (= £25.47 * 5.0 units)
Reusable pads
The average unit price per reusable pad is £7.46, based on 19 data points.
Multiplying the number of units from Section 2 by this unit price gives:
- £17.90 per year (= £7.46 * 2.4 units)
- £178.99 per 10 years (= £7.46 * 24 units)
- £671.27 per lifetime (= £7.46 * 90 units)
Underwear
The average unit price per underwear is £17.25, based on 132 data points.
Multiplying the number of units from Section 2 by this unit price gives:
- £31.93 per year (= £17.25 * 1.9 units)
- £319.26 per 10 years (= £17.25 * 19 units)
- £1,197.24 per lifetime (= £17.25 * 69 units)
Waste
All weights exclude packaging.
Reusable products are assumed to be disposed of clean (r.g., underwear are washed to be put in a textiles recycling bin), while disposable products include the menstrual fluid.
Single-use products
The weight of each single use product is based on:
- The weight of an unused product
- Plus the maximum weight of menstrual fluid that a product can absorb
- Scaled to 80% under the assumption that not all products are completely maxed out
The average weight of an unused pad is 6.7 grams, based on 5 data points.
The average weight of a disposed pad is 13.0 grams.
The average weight of an unused tampon is 2.3 grams, based on 5 data points.
The average weight of a disposed tampon is 9.2 grams.
The average weight of disposed single use items used in the modelling is 11.1 grams.
Multiplying the number of units from Section 2 by this average weight gives:
- 2.8 kg per year (= 11.1 g * 253 units per)
- 27.9 kg per 10 years (= 11.1 g * 2,526 units)
- 104.8 kg per lifetime (= 11.1 g * 9,472 units)
Cup
The average weight of a cup is 13.4 grams, based on 15 data points.
Multiplying the number of units from Section 2 by this average weight gives:
- 0.002 kg per year (= 13.4 g * 0.13 units)
- 0.018 kg per 10 years (= 13.4 g * 1.3 units)
- 0.067 kg per lifetime (= 13.4 g * 5.0 units)
Reusable pads
The average weight of a reusable pad is 35 grams, based on 5 data points.
Multiplying the number of units from Section 2 by this average weight gives:
- 0.08 kg per year (= 35 g * 2.4 units)
- 0.84 kg per 10 years (= 35 g * 24 units)
- 3.1 kg per lifetime (= 35 g * 90 units)
Underwear
The average weight of underwear is 71.2 grams, based on 10 data points.
Multiplying the number of units from Section 2 by this average weight gives:
- 0.13 kg per year (= 71.2 g * 1.9 units)
- 1.32 kg per 10 years (= 71.2 g * 19 units)
- 4.9 kg per lifetime (= 71.2 g * 69 units)
Greenhouse Gases (GHG)
Single-use products
The average GHG emissions per single-use pad is 0.029 kg CO2e, based on 11 data points.
The average GHG emissions per tampon is 0.021 kg CO2e, based on 13 data points.
The average GHG emissions per single use item used in the modelling is 0.025 kg CO2e per item.
Multiplying the number of units from Section 2 by this average GHG emissions gives:
- 6.4 kg CO2e per year (= 0.025 kg CO2e * 253 units per)
- 63.6 kg CO2e per 10 years (= 0.025 kg CO2e * 2,526 units)
- 238.6 kg CO2e per lifetime (= 0.025 kg CO2e * 9,472 units)
Cup
The average GHG emissions per cup is 0.7 kg CO2e per year of use, based on 8 data points.
Multiplied by 10 years, this equates to 7.5 kg CO2e per 10 years.
Multiplied by 37.5 years of menstruation per lifetime (see Section 1), this equates to 28.1 kg CO2e per lifetime.
Reusable pads
The average GHG emissions per reusable pad is 1.3 kg CO2e per year of use, based on 4 data points.
Multiplied by 10 years, this equates to 13.1 kg CO2e per 10 years.
Multiplied by 37.5 years of menstruation per lifetime (see Section 1), this equates to 49.1 kg CO2e per lifetime.
Underwear
The average GHG emissions per underwear is 2.4 kg CO2e per year of use, based on 5 data points.
Multiplied by 10 years, this equates to 24.1 kg CO2e per 10 years.
Multiplied by 37.5 years of menstruation per lifetime (see Section 1), this equates to 90.4 kg CO2e per lifetime.