At our house:
Annual Kentucky Derby party (sometimes this coincides with a Cinco de Mayo party) about 80 people.
Corporate Christmas party, about 30 people
4th of July lobster boil, about 50 people
Back to school cocktail party for parents, about 40 people
This doesn’t include the rando get togethers with 1 or 2 couples at a time.
I’ve never hosted a party for friends, but close family regularly gets together for birthdays and that is often at my house.
The whole idea of parties is pretty exhausting for me.
We host a gaming group every Friday night - between five and ten people.
We have at least one big party every year that is 50 - 120 people - my husband’s birthday party.
Every few years we rent a space and do a bigger hosted party - my fortieth, my husband’s fiftieth, we are thinking about doing it for our 25th wedding anniversary.
We used to host parties once or twice a year. 15 to 20 people, typically. We also got married at our house (70) guests. Our house is perfect for entertaining (as they say on TV) but we don’t really like people. I don’t think we’ve hosted a party for at least 5 years.
“Party” would have to be defined, I guess. We have a few people for dinner on occasion, and we recently did a farewell brunch for some neighbors who are leaving. But a party that is just drinking, socializing, etc.? Never.
Most of our parties are family-related. We don’t have friends over very often.
Every year we do:
Easter
Thanksgiving
Mother’s Day
Christmas
And all 6 of the grandkids’ birthdays (family parties). Some of the kids have birthdays that are close together so those are usually combined.
Most of the parties are potluck type.
Pretty much this^. Family events happen at our house 4-5 times each year, but always center around birthday or holiday meals. Not so much parties as get togethers. I don’t know that we have ever hosted a party with friends/neighbors/etc. We’re introverts, home by ourselves is where we recharge.
Our preferred social gathering is 1-2 other couples - up to a max of 8 including us.
Maybe every year or 2 we’ll end up hosting an “open house” for family, that may run up to 20 people. We dislike hosting such events, but feel we have to every once in a while around holidays and such.
The last big bash we had was for my 40th - 19 years ago.
The neighbor behind us often has big neighborhood bashes. My wife and I sorta wish we were the sort of people who liked to throw our homes open to large crowds, but we just don’t. As a general rule, our preference is not to attend large gatherings either.
We’ve cut back on the parties the last 5 years due to space and money constraints. We’re finally getting back on our feet and so we’ll be hosting the family Thanksgiving this year and that should alternate every other year from now on which tends to be 12 people or so. In the spring I’ll be kicking back up my annual pig roast which tends to run about 50 people though the first year back may be a bit smaller. Besides that we normally host one or two other parties of about 15 people.
We were going to do 20 odd people for labor day but my remodel is going long and we can’t get the house done in time. We also are doing our first real birthday party for our oldest kid where she gets to invite her friends over.
I haven’t had more than two “parties” at my townhouse in the 35 years we’ve lived there. I’ve had people over, but we just don’t have the space or enough parking for a good-sized party.
I used to **go **to a ton of parties, especially with work friends. I’m retired now, but the last 5-10 years before I retired the number of parties seriously dropped off. I mean I used to have my choice of like four different Halloween parties every year, and usually about that many different Christmas/Holiday party/get-togethers. My last few years at work nobody threw parties.
How often? Other than e few family gatherings with less than ten people I never have. No longer do that as they aged out of life or moved elsewhere.
Not into crowds either, so I rarely attend these things.
Love giving dinner parties for 3-10 people and the occasional game night for up to twice that, but haven’t thrown a really big party since college, nor ever rented a venue for one.
I’d say, so rarely that my answer is effectively “never.”
We will sometimes host my wife’s family for holiday gatherings (Thanksgiving, Christmas, birthdays), but I don’t think of those as parties (YMMV on that 
), but as my sister-in-law is the one who has kids, those gatherings have been at her house more often than not for the past 20 years.
We do have people over to play role-playing games every few months, but again, I don’t define those as “parties.”
Never. We occasionally have people over, but nothing that I’d call a “party”.
ProTip: buy a package of party hats that you can distribute to your guests.