Image looks more like a belt of fire giant strength.

Equipped it to my paladin and DnD Beyond doesn't raise my strength over 20.  Anyone know if there's a way to fix that?

Lol. Simply lol  😆 

Make sure it's attuned, simply equipping it does nothing

I actually had to change something in the character settings, I think. I ended up overriding the score in the character creation. 

How can you assume that?

Tarrasque is a hella lot bigger tho.
A character with Powerful Build - the compensation for not having Large races - would be able to carry double that, around 870 lbs.

never give this to a fairy worst mistake of my life

I HAVE THE POWER!!!!!!

Quote from Helmut_McQuack >>

Quote from yogg_saron >>

thats becaus a draft horse is large thats 18×30 540

 Oh, that makes sense. Thanks.

It just doesn't make sense that someone with (almost) the STR of a tarrasque can only carry 435 lbs.

 Thats because Tarrasques are so big. Theres a weird quirk of physics where larger animals are actually able to carry less relative weight to their own weight. That is why ants can carry things much bigger than they are, but an elephant can't lift another elephant

go to your items and attune to it. you can equip it but unless you attune it, its effect wont happen

Look up Hammer of Thunderbolts. It can get your player to thirty when combined with this item or the cloud giant variant.

It wasn't just attunement. It was something in the settings that I had to fix.i think I had to override the strengths score.

Has to be +9 following the standard trick to determine ability mod: subtract 10 from the number divide by 2.  29-10=19, 19/2=9.5, round down to 9

my fairy barrbarian will actually be strong now (small sized)

Yeah, but if you strap that horse up with a belt of storm giants strength and you cast awaken on it, you've just made a new super hero. Super horse, with the strength to carry 870 lbs!

I appreciate the second line, just in case my pc already had 29 strength

Imagine sticking this on a Moon Druid. If your DM is nice about animals wearing human-sized items, you could do silly things like being a mouse with 29 Strength.

way too op bro

paladins can dump strength with this and go for +5 dex and serpent scale mail (20 ac)