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How To Split Expenses with Roommates, Spouses and Family

how to split expenses with roommates above two young women talking to each other while sitting on a purple couchSplitting expenses is often a touchy topic when you’re living with a significant other, roommates or family.

If everyone doesn’t agree it can get pretty nasty fast.

There are a few ways to split expenses between yourself and those you live with but I’m going to highlight four of the most common ways today.

Splitting expenses really isn’t an issue if you’re living with your significant other, husband or wife and have combined finances.

However, a lot of people keep separate finances when they’re dating (as we did) and some continue this after they get married (we did not).

Want to know how my wife and I used to split our expenses when we were dating? Make sure you read through to the end of the post.

Split Expenses Equally

Splitting expenses equally is the easiest method to calculate because all you do is simply divide the expense by however many people will be paying for it. While it is easy to calculate, that doesn’t mean it is going to be a popular decision.

This method can work well for items that get equal use such as parking. It seems to work well for spouses or significant others living together because it is simple and doesn’t require a lot of thought.

It doesn’t always work as well for roommates or family living together though because the use of the item being paid for is not always used equally by everyone.

Split Expenses Based on Usage

Splitting expenses based on usage makes a lot of sense from a practical standpoint but it doesn’t always sit well with the people you share living space with. It can also be extremely difficult to calculate.

This method is great when you have roommates. I had two roommates in a three bedroom apartment once and we used this method often. The bedroom sizes in the apartment were not equal so it didn’t make sense to split the rent equally.

Another expense this worked well for was our cable bill. We each had different cable receivers in our bedrooms. The receivers had different costs so we split the cable bill based on each individual roommate’s use.

This didn’t work for food expenses because we couldn’t measure consumption accurately. Instead, we all bought our own groceries and asked if we wanted to use some of our roommate’s food.

We couldn’t split the electricity bill based on usage either but I think the only reason we didn’t do this because we couldn’t have individual meters on all of our outlets! 

I’m joking… only to a point. One of my roommates probably would have liked splitting the electric bill based on usage.

Split Expenses Based on Income

Splitting expenses based on income seems to be popular among spouses and significant others.

Incomes can be very different in some relationships and some people feel it is fair to split expenses based on the ratio of income between the people living together.

For instance, if a boyfriend and girlfriend who lived together made $25,000 and $75,000 respectively then shared expenses would be paid 25% by the boyfriend and 75% by the girlfriend.

Bills like rent, utilities, and groceries can all be easily split this way. Utility bills are even easier to split if you use budget billing to level out the monthly charges.

This might not make as much sense if you are splitting bills with roommates but could work if you’re living with multiple generations of family.

It could cause some arguments when it comes to expenses that are solely for one person. For instance, if a couple each owns their own cars and drove their car exclusively it might not make much sense to split that expense according to income.

If you use some common sense and only split expenses that are actually shared this might work out for your situation.

Contribute What You Can

The method of contributing what you can is normally what ends up happening when a family is forced to live together or a spouse or roommate loses a job.

It takes a very generous person (the person paying the bigger share) and an honest person (the person contributing what they can) to make this work without resentment.

This is rarely a planned method of splitting expenses and it requires a lot of effort by both parties. Normally this works best if you set some ground rules.

If a person is just contributing what they can, any spending that isn’t paid toward shared expenses can cause an argument.

If a person hasn’t contributed to rent but instead purchased a new piece of jewelry arguments could be right around the corner.

How We Split Our Expenses

We have split our expenses a few different ways over the years. We changed our methods based on what made the most sense for us at the time.

When we were dating and both in college I’d pay for our dates (for the most part) and we’d each pay for our own gas to visit each other since we went to different colleges. We split our expenses equally during this time period.

I then graduated from college and was working full time while my then girlfriend remained in college.

During this time I paid for most of the expenses and my girlfriend would pay for some smaller expenses because she was contributing what she could.

I’d often pay her for her gas money to come visit so it wouldn’t add to her student loans. During this time period, we used the contribute what you can method.

Before we were married, but when we were both in the same place and lived together we split our expenses equally. We didn’t make the same amount of money but we felt this is the best way to split the expenses at this time.

We had a very low total cost in regards to shared bills and could both handle the amount of expense without any financial difficulty at the time.

We kept our finances separate since we weren’t married. However, splitting expenses is no longer an issue because we got married and we now combine our finances!

Do you live with roommates, a significant other, or family? How do you split the expenses in your household? What works and what doesn’t?

Share as much detail as you feel comfortable doing so we can understand why different methods work for different people and different situations!


Sunday 18th of November 2018

I am 49 years old I have a 15-year-old daughter and a 26-year-old son who is mentally disabled my daughter is in high school and I am also disabled We both stay home all day because we are disabled he is on the computer 24 seven doesn’t help around the house and I do all of the cooking in a lot of the cleaning and laundry and going shopping and doing this and doing that the things that we have to do to keep. We both stay home all day because we are disabled he is on the computer 24 seven doesn’t help around the house and I do you all of the cooking in a lot of the cleaning and laundry and going shopping and doing this and doing that the things that we have to do to keep your partner I have always split the bills into third but the bills that may split into thirds it is only the rent electricity the Internet the gas and that’s it man I charge him $10 for doing his laundry He makes more in disability than I do like to $155 more in disability then I do so I am continually feeling like it’s not fair to me to have all of my bills plus putting it in thirds which really means that I pay 2/3 because I have my daughter and he only pays a third Does that sound right to you or should I let those bills that I listed in half

Lance Cothern

Sunday 18th of November 2018

Things like this are always tough because there are so many factors involved. Honestly, there are only two people capable of paying for internet and electric and it sounds like you do most of the housework so I would think those should definitely be 50/50. The rent may be different because you and your daughter are using 2/3rds of the bedrooms I would guess. However, once the daughter moves out or starts working and living at home after school that would make it 1/3rd each or 1/2 and 1/2. That's just my two cents.


Monday 16th of July 2018

My 2 sisters are buying a house together! 1 Sister has a boyfriend who will be moving with them (they will share a room) + have an addition room for gym. My 2nd sister has 1 child (12 year old) and they will have 2 rooms. How should the mortgage be split? 3 ways or just split in 1/2 between my 2 sisters with the boyfriend paying my sister? If split 1/2 between sisters doesn't 1 sister benefit while the other doesn't but still has to share the house with him? Any advise or suggestions appreciated!

Lance Cothern

Monday 16th of July 2018

This is tricky, like most situations. Honestly, you can do it one of two ways. Personally, since they'll both get 2 bedrooms, they should split the cost in half. Yes, the boyfriend living there is another person, but so is the 12 year old. The other way to look at it is a per adult standpoint. Then the sister and boyfriend would pay 2/3rds of the cost. But is that fair since the sister and boyfriend have to live with the 12 year old, too? And what happens if they boyfriend and sister break up? Will the mom have to increase her share of the bills? Buying a house together can be a nightmare in these situations. If they can't both agree upon a fair way to split expenses now, I'd highly suggest not buying the house together.

Vicki Haberman

Monday 28th of May 2018

I'm 70 and disabled. A year ago I bought a home with cash. I made the mistake of adding my son and daughter in laws names as well as mine on the title. I also paid $30,000 to add my own room and bath with seperate entrance on the back of the house. I also pay them $300 a month cash and allow them to use my food stamp allowance. I buy my own food and other supplies. Now my son says I'm not shelling out enough money and should also pay half of taxes, insurance, and electric, (I have my own air unit). He has threatened to cut off my cable, internet, phone. What should I do? Stop paying the $300? Take back my food stamp allowance? I'm wondering if I should also get my own electric meter and cable. My total monthly income is $750. I need help. Thank you for any help you can give. I live in Gainesville Texas.

Lance Cothern

Monday 28th of May 2018

Hi Vicki,

That sounds like a really tough situation. It's hard to tell what the original arrangement was. However, if you're buying your own food and other supplies, I would use the food stamp allowance to buy your groceries and then use the $300 plus the money you would have spent on food to put toward your share of the insurance/taxes/electric. I don't know how he could cut off your cable/internet and phone without cutting of his own, as well. I hope you can find a situation that works for both of you, but explaining you live on a limited income and showing your son where the money goes may help, too.


Thursday 5th of January 2017

My biggest issue at the moment is if we were to move in with another family how would the costs be calculated it would be my husband and I (joint fianances) and we'd have friends who are a couple and their daughter who's 11 moving in, both couples with their own room, the child with their own room and a spare room for guests. Do the other donwe include the child when factoring out rent, electricity and water in my and my husbands opinion we would divide all costs by the number of people occupying the house but does that sound right when it involves an 11 year old child too?

Lance Cothern

Thursday 5th of January 2017

Lenny, I personally think your husband is right. They are providing for three people and three people take more resources than two. They'll be taking up more space in the home, because without the child, you could have rented a three bedroom home that would have used less electricity and would be cheaper to heat and cool. A third person will use more water for showers, etc. Even though they are a child, the child's parents are responsible for providing for them and you shouldn't have to subsidize the costs of raising their child.

Lori Ann German

Saturday 10th of December 2016

I was facing a move due to decreased income. My eldest daughter (who doesn't work) and her boyfriend were expecting a baby and living in a not so desirable situation. I also had my 18 year old daughter living with me. It was mutually decided that my daughter and her boyfriend move in with me and my other daughter. The "couple" have the master bedroom; the baby the smallest room for her; my other daughter and I have our own rooms. We were splitting everything by 1/3 rds since 2014. Recently my 18 year old has had her friend stay with her several nights/days a week. My eldest feels that this friend should pay her way and wants to split everything by 4. I disagree as she, boyfriend,baby count as 1 unit, with him earning their income,daughter and somewhat live in friend should count as one unit ( yes they both work minimum wage jobs at varying weekly hours) and I count as one unit. I don't take into consideration that they utilize 1/2 the bedrooms, the whole living room has been baby proofed thus my personal items are very quickly disappearing to the point I pretty much live My room. What would be a fair way to divide expenses?

Lance Cothern

Tuesday 13th of December 2016

Situations like this are hard. I think the easiest way to think about it is how would you divide the expenses if it weren't family? If someone was taking up half of the apartment, I would think they should pay half of the rent. Of course, the family dynamic makes things more complicated. In the end, you have to do what works for you.