How this instrument works
This is a straightforward multiplication: how many products a single cycle typically takes, times how many cycles happen in a year, times what each product costs. The result estimates what pads, tampons, liners or similar disposable products actually add up to over twelve months — a figure that's easy to underestimate when you're only ever looking at one box at a time.
The defaults reflect commonly cited figures rather than a fixed rule. Research summarized by the Ballard Brief at Brigham Young University notes that roughly 70% of people who menstruate use tampons and go through an average of about 20 per cycle, which is where this calculator's default product count comes from. Cycles per year defaults to 13, derived from the roughly 28-day average cycle length that the Cleveland Clinic reports (365 days ÷ 28 ≈ 13), though anyone with a shorter, longer, or irregular cycle — or using cycle-suppressing birth control — will see a different real number.
None of these defaults are universal, which is exactly why every field is editable. Flow, product type, and personal preference all shift the real count: someone using menstrual cups or reusable cloth pads has a large upfront cost but a near-zero recurring one, while someone combining pads and tampons, or managing a heavier flow, may need more products per cycle than the default assumes. Treat the output as a personal budgeting estimate to adjust with your own numbers, not a universal statistic.
- Enter Products used per cycle — the count of pads, tampons or liners a typical cycle takes for you; the field defaults to 20, a commonly cited average.
- Enter Cycles per year — defaults to 13, based on a roughly 28-day average cycle; lower this if your cycles run longer or are suppressed by certain birth control.
- Enter Price per product, $ — check a box's total price divided by the count inside to get an accurate per-item figure.
- Read Estimated annual cost, $ — the three inputs multiplied together.
- Compare the result against buying in bulk or switching product types, since both the per-item price and the products-per-cycle count directly scale the annual total.
Worked example — 20 products, 13 cycles, $0.25 each
Enter 20 for Products used per cycle, 13 for Cycles per year, and 0.25 for Price per product, $ — the calculator's own defaults, based on commonly cited averages for tampon use and cycle length. Estimated annual cost comes to 20 × 13 × 0.25 = $65.00, a realistic single-year figure for someone matching those averages.
That $65 is only one year. Multiply a similar annual figure across the several decades many people menstruate and the total compounds quickly — which is part of why the Ballard Brief's period-poverty research separately estimates lifetime menstrual-product spending in the thousands of dollars once decades of cycles are added together, even though any single year's cost looks modest on its own.
Questions
Why does the calculator default to 20 products per cycle?
It's based on research summarized by the Ballard Brief at Brigham Young University, which reports that roughly 70% of people who menstruate use tampons and go through an average of about 20 per cycle. That's a population average, not a personal guarantee — flow, cycle length, and product type all shift the real count, so replace the default with your own typical usage for a more accurate estimate.
Why does the calculator default to 13 cycles per year?
It comes from the roughly 28-day average menstrual cycle length reported by the Cleveland Clinic: 365 days divided by 28 works out to about 13 cycles in a year. Anyone with a shorter or longer average cycle, an irregular cycle, or cycle-suppressing birth control will have a different true number and should adjust this field accordingly.
Does this calculation work for menstrual cups or reusable pads?
Not directly, because those products break the per-cycle repeat-purchase pattern this formula assumes. A cup or reusable cloth pad involves a larger one-time cost but little or no recurring per-cycle spending afterward, so comparing it to disposables means dividing that upfront cost by however many years you expect it to last, rather than multiplying by cycles per year.
How much do period products cost over a lifetime, not just a year?
It depends heavily on individual usage and pricing, but the Ballard Brief's period-poverty research estimates total lifetime menstrual-product spending in the thousands of dollars across roughly 40 years of menstruation — a figure that comes from compounding a modest annual cost, similar to this calculator's output, across several decades rather than from any single year looking expensive on its own.
Are period products taxed differently than other everyday necessities?
In some US states, yes. A number of states have historically applied standard sales tax to menstrual products while exempting other health or grocery necessities — often called the 'tampon tax' — though a growing number of states have passed exemptions in recent years. State tax treatment isn't built into this calculator's math and is worth checking separately if you're budgeting precisely.
What's the easiest way to lower my annual period-product cost?
The formula shows the two levers directly: price per product and products used per cycle. Buying in bulk or switching to a lower-cost brand reduces the price input, while switching to a reusable product like a menstrual cup or cloth pad can shrink the recurring products-per-cycle cost to near zero after the initial purchase, at the expense of a larger cost upfront.