Are these micron/mm/inch converters exact?

Yes for pure unit math — unlike mesh charts which depend on wire cloth standards.

When should I still use mesh charts?

Whenever you quote procurement specs tied to ASTM E11 / ISO 3310-1 style sieves.

Download it from the mesh-to-micron chart page.

Pair geometric unit math with woven mesh references — sieve openings remain approximate except on certified instruments.

Mesh → micron calculator

Micron → mesh calculator

Mesh chart & CSV

Printable mesh chart

Mesh → mm hub

Mesh size primer

ASTM / ISO sieve primer

Micron → mm

mm → micron

Micron → inch

inch → micron

Are these micron/mm/inch converters exact?: Yes for pure unit math — unlike mesh charts which depend on wire cloth standards.
When should I still use mesh charts?: Whenever you quote procurement specs tied to ASTM E11 / ISO 3310-1 style sieves.
Where is the CSV chart?: Download it from the mesh-to-micron chart page.