Are 50-50 marriages exactly 50-50?

One of my friends and I were recently discussing what success in a 50-50 partnership looks like. Does it mean that each person does exactly 50% of household work at all times? Or, that over the course of a marriage, each partner does roughly 50% of work? Is there a world in which someone could be in an equal partnership but do more or less than 50% of household labor and/or childcare?

I think the answer to the above questions is yes! When I think of a 50-50 partnership, I think of egalitarianism, but I also think about fairness. It’s rare that at any given moment, household work is split exactly 50-50 - this usually ebbs and flows, sometimes daily.

What we’ve tried:

While overall, Jason and I have tried to make things equal, we’ve tried to prioritize fairness on a day-to-day basis. We’ve discussed our mutual belief that the division of household labor at any given moment can and should be influenced by some of the following factors:

Hours worked: Jason and I generally both work long-ish hours, but because my workload tends to be cyclical, I occasionally find myself in a slower period where I’m working a bit less than usual.
Whenever that happens, I try to take household work off of Jason’s plate, particularly if he happens to be in an especially busy period. We’re lucky that so far, if both of us are extra overloaded - from work or otherwise - we’ve been able to outsource more to compensate (e.g., ordering more takeout vs. cooking) or let a few things drop (e.g., temporarily accepting a previously unacceptable level of clutter). I know it would be significantly more challenging if we were faced with dropping something far more consequential than extra clutter.

Business travel: Before the pandemic, I traveled a bunch for work - monthly trips to the opposite side of the country and usually a couple of international trips a year. I don’t count all travel time as work (thanks to my Kindle!), but lots of traveling and time-zone switching can be exhausting, so I deeply appreciated whenever Jason had dinner waiting when I arrived home after a long flight.
One-off time consuming projects: When Jason and I were engaged, he took on substantially more household work because I was doing the bulk of wedding planning. Similarly, when Jason started working for himself, I tried to take over as many “Jason domains” as possible.
Strengths and weaknesses: I enjoy cooking, so I pretty quickly became the default cook in our relationship. Jason has a computer science background, so he does all tech support. We’ve been lucky (so far!) that we don’t have a chore that both of us hate; I don’t mind doing the dishes and cleaning up after cooking, and Jason actually likes taking out the trash.
Preferences: A few months ago, Jason and I were discussing whether we’d want to stay in NYC long-term and, if not, what kind of place we’d want to go. Jason mentioned he’d always loved the idea of a big yard. Maintaining a big house and yard to me, at least, felt like a nightmare scenario - I had visions of whole weekends spent at Home Depot picking out paint colors and weeding garden beds (gardening is so foreign to me, I’m not even sure that’s a thing). It was a good foundational conversation about how we’d approach a situation where one person’s preference (e.g., a big house and yard) involved a lot of extra work.
Flexibility: Sometimes, one of us is sick. Or one of us hasn’t had a chance to work out that day. Or someone is really behind on sleep. We both try to be as flexible as possible and pick up slack for each other.

How do you define a 50-50 partnership? Let me know in the comments below!