To have a more peaceful, loving relationship that has the potential to last for a lifetime, don't count and don't measure.
Don't divide anything "fifty/fifty." Forget that concept. Give what you have. Do all you can do. Give/do 80% when you can, but only measure it vaguely, at a squint, and then forget about it. If you aim for half, there will be resentments. If you aim for 100%, small failures will seem larger than they need to be, so don't do that. You can succeed at "lots" without measuring.
If each of you gives as much as you can, your shared needs will be fulfilled more quickly, more easily, and more often.
Be generous with your patience. Life is long. People change, and more than once.
I wrote that for a young friend getting married, and I quoted it here:
Becoming a Better Partner
photo by Vlad Gurdiga