Twin to king converter kit:
what do you actually need?
Most kits bundle four things. You usually need one of them. Here is what each part is for, and which one does the work.
What is a twin to king converter kit?
A bundle sold to turn two twin mattresses into one king bed. Four parts are common, and they do not all do the same amount of work:
- The connector strap joins the two mattresses so they stop drifting. This is the part that fixes the problem.
- A foam wedge fills the seam from above. It solves the same problem a second time, less well.
- Non-slip pads stop each mattress moving on its base. Useful only if that is also happening.
- A king fitted sheet over both. Not part of the fix, but it is what makes the join invisible.
Buy the connector and a king fitted sheet, and you have converted the bed. The Bedbinder Deluxe is the connector, $49.95, fitted in 60 seconds.
Which part of the kit does the work?
Kits look like better value than a single item. Read the parts list and that changes.
| Part | What it is for | Worth it? |
|---|---|---|
| Connector strap | Pulls both mattresses together so the seam cannot open | Yes, this is the fix |
| Foam wedge | Sits in the seam and fills it from above | Duplicate, and it slides |
| Non-slip pads | Grip between mattress and base | Only if a mattress also slides on its frame |
| King fitted sheet | Covers both mattresses as one surface | Yes, but buy the size you want |
| Cable ties or hooks | Ties the two frames together | Joins the frames, not the mattresses |
Scroll sideways on mobile for the full table.
The wedge and the connector are the awkward pair. They are two answers to one question, and a kit that contains both is telling you it is not sure which one works. A wedge fills the gap and moves with the bed. A connector removes the reason the gap appears. You are paying for two attempts at one job.
Do two twin beds really make a king?
This is where a conversion quietly goes wrong, and it is a five inch problem.
| What you have | Together | Compared to a King (76 x 80) |
|---|---|---|
| Two Twin XL | 76 x 80 inches | Exactly a standard King |
| Two regular Twins | 76 x 75 inches | King width, five inches shorter |
| Two Fulls | 108 x 75 inches | Far wider than a King, no sheet fits |
Two Twin XL is the combination the whole category is built around, and it is why American split king beds exist. Two regular Twins still work, but a King fitted sheet will be slack at the foot end. That is cosmetic, not structural, and worth knowing before you order the sheet.
More on the measurements, bed by bed, in the sizing guide.
What you give up on an adjustable bed
Three customers left us reviews about this, and they were right to. Better you read it here than find out after delivery.
If you have a split king on adjustable bases, you bought it so each side could move on its own. A connector joins the mattresses. Those two wishes pull against each other, and no product makes that go away.
- Only the head ends adjust: the two work together. The heads still raise independently with the band fitted underneath.
- Head and foot both adjust: they do not. The 80 cm band fights the foot section. A narrower 60 cm version is made for that setup, and it is not in our own shop, so ask us and we will point you the right way.
- You want separate twin fitted sheets: you cannot also have the mattresses joined. The band goes under both, so the bedding goes over both. A King fitted sheet, or a split-head King, is the way round it.
We would rather lose the order than have you find that out on a Tuesday night with the bed half made.
Converting the bed, start to finish
Across the seam, straps underneath, three buckles. About 60 seconds, no tools, and it comes off just as fast.
9.3/10 · more than 250,000 sold
Mostly bought for the spare room
Three American customers who converted two twins rather than buy a king.
Two beds in one.
“This works so well for connecting two twin beds together to make one Cal king. Now my guest room is so versatile to accommodate my guests.”
Use what you already have.
“Perfect solution for the extra bedroom. Easily converts two twins to a king which is comfy and sturdy. Great design and value.”
Was afraid it would move.
“I was afraid that it would not stay in place, or that I would be able to tell that it was on. I had bought mattress protectors for both twins, then applied twin mattress pads, followed by the king binder. I like it!”
Questions before you buy a kit
Including the parts we would tell you to skip.
What is in a twin to king converter kit?
Usually four things: a connector strap that joins the two mattresses, a foam wedge for the seam, non-slip pads, and sometimes a king fitted sheet. The connector is the part that does the work. The rest is filler in both senses of the word.
Do I need the whole kit or just one part?
In most cases one part. If your two mattresses drift apart, you need the connector. The wedge and the connector solve the same problem in two different ways, and buying both means paying twice for one fix.
Do two twin beds actually make a king?
Two Twin XL mattresses make a standard King: 76 by 80 inches. Two regular Twins make 76 by 75 inches, which is King width but five inches shorter, so a King fitted sheet will be loose at the foot end.
Will a king sheet fit over two twin mattresses?
Over two Twin XL mattresses, yes, and a King fitted sheet over both is what makes the join disappear. Over two regular Twins it fits the width but not the length. Split-head King sheets are the other option if you want the head ends to move.
Can I convert two twin beds to a king on an adjustable base?
If only the head ends adjust, yes. If the head and foot of each side both move, a connector fights the frame, and there is a trade-off nobody mentions: joining the mattresses means you cannot also keep separate twin fitted sheets on each side. Several customers found that out after buying.
How long does converting two twins to a king take?
About 60 seconds for the connector itself. Lay it across the seam, pull the straps under both mattresses, click the buckles. Making the bed afterwards takes longer than the conversion.
Is a converter kit cheaper than buying a king mattress?
By a wide margin. The Bedbinder Deluxe is $49.95 against several hundred for a King mattress, and you keep the two twins for the guest room, which is the reason a lot of people go this way in the first place.
Can I convert the bed back to two twins?
Yes, and faster than putting it on. Unclip the three buckles and pull the band out. Nothing is glued, screwed or permanent, which is what makes this work for a guest room that changes with the visitors.
Next steps for a twin to king setup
Three pages that go further than this one.
The method, step by step
How to make two twin beds into a king, including what fails and why.
Read moreWhat size do you end up with?
Two twins together: the measurements, and which sheet actually fits.
Read moreWhat a connector is
Band width, buckles and strap count: what separates one connector from another.
Read more
One kit part, or a new king mattress?
Two twins, joined in 60 seconds, and back to two beds just as fast.
Not happy after 90 nights? Full refund, no questions asked.