✅ Life List Completion Calculator

Enter how many species you've seen and the size of the list you're working from (a regional checklist, state list, or world list) to see your completion percentage.

Species seen

Total species on list

Your count against your chosen list

The page divides what you have recorded by the size of the list you are working from and shows what is left:

completion % = species seen ÷ total on list × 100
remaining    = total − seen

150 ÷ 700 = 21.4%      550 still to go

On a 700-species list each new bird is worth 1/700, or 0.14 of a percentage point, so reaching 50% means finding another 200. The remaining figure never goes below zero, but the percentage is not clamped: enter 150 against a total of 120 and it will report 125.0% while showing 0 remaining, which is the sign you have paired a count with the wrong list.

Choosing the denominator

Say which list you mean. A world total, a state checklist and a garden list give three very different percentages from the same sightings.
Totals differ by authority and by year. IOC, Clements and BirdLife each publish their own world checklist, and every revision splits and lumps species, so both the total and your own count can move without you leaving the house.
Expect the curve to flatten. The species left on any list are by definition the ones you have not caught up with, and which of them are realistically findable depends on your region, the season and the year.

Use the list your records already follow — whatever taxonomy your notebook or eBird account uses — rather than mixing a count from one source with a total from another.

Frequently asked questions

What percentage of the world's birds have I seen?

Divide your life list by your checklist's world total, which sits somewhere around 11,000 species depending on the authority and the year. On that basis a 700-species life list is roughly 6%.

Why did my completion percentage change when I saw nothing new?

A taxonomic revision. When one species is split into two your count can rise, when two are lumped it falls, and the list total moves at the same time.

Can the result go above 100%?

Yes. The percentage is a plain division with no upper limit, so a count larger than the list total reports over 100% even though the remaining row stops at zero. Check that both numbers come from the same checklist.