Is there an average amount? It’s widely accepted that the average person loses between 30 and 40 milliliters, or two to three tablespoons, of blood during menstruation. But some researchTrusted Source suggests that this figure may actually be closer to 60 milliliters, or about 4 tablespoons.
The span of “normal” blood loss is wide, so some people may have periods that are lighter or heavier than what’s considered average. If you aren’t experiencing severe cramping, nausea, or other side effects, your individual amount of blood loss is likely normal.
If you want to figure out where you fall on the menstrual spectrum, read on. We’ll walk you through how to calculate your monthly blood loss, symptoms to watch for, and when to see your doctor.
How can you tell how much you’re actually bleeding?
You expel more than just blood during menstruation. Your menstrual fluid also contains a mix of mucus and uterine tissues, which can add volume to your overall fluid loss. That’s what makes measuring blood loss tricky.
But it’s definitely possible. The hygiene products you use can help you get a rough estimate of your overall flow. And if you want an accurate account of pure blood loss, math is on your side.
If you use menstrual cups
One of the easiest ways to measure fluid loss is with a menstrual cup. You don’t have to deal with absorption issues. Some cups even include volume markings for easy reading.
Depending on the brand and type, your menstrual cups may hold anywhere from 30 to 60 milliliters at a time. If your cup doesn’t have volume markings, you can research the manufacturer’s website to find out more.
When it’s time to empty your cup, take note of how much fluid it contains. You can record this as a note in your phone or keep a log. Then empty, wash, and reinsert as usual.
Continue to update your log for your next three or four periods. This should give you enough data to determine your average menstrual loss per day and per week.
You may find that your entire period loss is greater than 60 milliliters. That’s because tissue, mucus, and uterine lining add volume to your flow.
If you use tampons, pads, or period underwear
It’s a bit harder to measure total menstrual loss when you use absorbent tampons, pads, or period underwear, but it can be done.
First, take into account the item’s fully soaked capacity. Regular tampons, for example, hold 5 milliliters of fluid. Super tampons hold double that.
If you lose 60 milliliters during your period, you may soak through 6 to 12 tampons depending on the size you use. If you lose half of that, you’ll likely use fewer.
You can keep a log to help you get a better idea of how much you’re losing. You should note:
- What product you’re using and its size
- How often you have to change it
- How full it is when you change it
Logging this info for your next three or four periods will give you enough data to calculate a reasonable estimate.
If you can help it, avoid fully soaking an absorbent product. Pushing a tampon or other product to its limit may result in a leak or other unwelcome side effects. The general rule of thumb is to change tampons, pads, and underwear every four hoursTrusted Source.
If you want to calculate the actual blood content
First, it’s important to understand one very important element of menstrual flow: You’re not only losing blood.
One study found that a period flow is 36 percentTrusted Source blood and 64 percentTrusted Source other elements, such as:
Tissue,Uterine lining, Mucus, Blood clots
With this in mind, you can multiply your total loss by 0.36 to determine the approximate amount of blood you’ve lost. Subtracting this figure from your total loss will give you the amount of other materials.
For example, if you collect 120 milliliters of menstrual fluid, multiply that by 0.36 to get a total blood loss of 43.2 milliliters. That’s well within the “normal” range of 30 to 60 milliliters.
If you subtract 43.2 milliliters from 120 milliliters, you find that your menstrual flow contained 76.8 milliliters of other components.
When is bleeding considered heavy? | When is bleeding considered heavy?
Some guidelines say a period is “heavy” when you lose 60 milliliters of blood; others put the number higher, closer to 80 millilitersTrusted Source.
Heavy bleeding, or menorrhagia, isn’t always a cause for concern. Treatment typically isn’t necessary unless it’s interfering with your daily life or you’re experiencing other symptoms.
See your doctor if you:
- Soak through one or more tampons, pads, or cups per hour for several hours
- Need to use double protection, such as a tampon and a pad, to prevent leaking
- Bleed for more than seven days
- Pass blood clots larger than a quarter
- Have to restrict daily activities because of your period
- Experience, fatigue, shortness of breath, or other signs of anemia