How much rent would I pay?

I think you are being ripped off, and taken advantage by the jerk who you first roomed with.  Tell him that you two have decided that it makes no sense for two people to share the small room so it is going to be his and you and this other guy are taking the large room.  How you three split the rent is up for discussion.  However, if he won't share in cleaning, then you are deducting $40 a month from him to be split by the other two.  Taking out the garbage does not amount to the same time and effort as cleaning.

The 30% Rule Explained: How Much Should You Pay for Rent? In simple terms, the 30% rule recommends that your monthly housing costs not go above 30% of your gross monthly income. So, if you gross $5,000 per month, the max you should be paying for housing costs, including rent, is $1,500.

YOU are the one that doesn't understand basic language or math.

387-288 = 99 ....NOT 50.  that is 99 MORE than you.

splitwise.com seems like a joke if it says your rent should drop from $283 to $240 (split between the two sharing the room) by bringing in another person who is using more common space.  The rent for the shared room should be going up.  You'd still be saving money b/c you'd be splitting a slightly higher number, but the per room cost certainly shouldn't go down.  That's nonsense.  Your roommate is giving up common space (kitchen, bath, living room, etc) and you want to charge him more?  Yeah, the site is stupid.  

Your rent is not tied to the cleaning habits of the people living there.  That's a separate issue which every roommate deals with.  You sound like you have a lazy slob.  It's a live and learn experience.  When the lease is up, then you look for a new place with someone else.  

--edit--

Basic math:  If rent is $675, then half is $337.50.  If he is going to pay $50 more than you, then the split would be $362.50 & $312.50  (subtract the two and get $50 more.)  That's how it's usually expressed. Your math comes to $100 more in the common usage.

Also we did work it out, he agreed we can pay 150 each. I genuinely don't think he's getting ripped off and some of you are thinking he is, hence why I made the post. Again name calling, you all really need to grow up. Thanks have a nice day.

Incompatibility is the far bigger issue here than money.  And that is the problem with roommates.  The other problem is that YOU agreed on the extra amount he would pay and the extra LESS that you would pay.  Now you want to renegotiate that amount and he does not want to.  What some website says does not mean you can renegotiate. He is under no legal obligation to change the agreement.

Approaching renewal time, you can renegotiate and if you can't agree, you don't renew and you all move. But it sounds like even if you get the money split YOU think is fair, you're not going to get the effort out of that guy that you want, and you can't force it out of him. So until the lease ends and you go your way and he goes his, you keep paying what you agreed to pay at the beginning. This website is meaningless after the fact.

You were already told that there is no law on splitting rent. How you split it is 100% what ever the roommates agree to.  If you cannot agree then you should not be living together.

How much or how little cleaning someone does has nothing what so ever to do with rent. 

It does not matter have big the bedrooms are.

The information from yesterday has not changed.

Large room = $275

Small room person 1 = $200

Small room person 1 = $200

Your room is not 65SF.  Do you know how small that is? about 6.5' x 10'.  Seeing that a twin bed is about 40" x 78", you aren't fitting two people in that room.  And it's unlikely that even you are in a room that small. 

- If two people are going to being the room without bunkbeds it's go to at least be "normal" (10'x10') which gives about 2 feet between the beds.  

Besides Splitwise doesn't take into consider 3 people living in a 2 bedroom.  You don't get to split 1/2 the rent of the smaller room because you have all the same access to the common space.

I didn't say you ripped off the other guy.  He agreed to it. That's not ripping him off.  I said I don't know why he agreed to it. 

Why are you so such a cheapskate?

You mean you didn't get the answers you wanted that people didn't agree with you

Signed room mate agreements BEFORE you start living with other people is required along with a rota of who does what/when, part of that roommate agreement is who pays what rent...so EVERYTHING is agreed and signed, you don't wait until there are issues, you do it before so these silly, immature issues don't get worse and cause more serious issues......... the basic is you don't live with other people and expect them to live the same way as you and if you do you have to be flexible and tolerant

Genuinely, I don't care. Because I'm not living in the space.

This is something to be discussed and agreed between you three. You can use SplitWise as a guide for best practice, but you still need to agree it.

(Also presumably your new partner will be on the lease if you're renting)