How do you convert ton of asphalt to square meter?

depends on the density. Asphalt density is typically between 2000 to 2400 kg/m³

1 tonne = 1000kg

per cm of thickness and 1m² of area:

Tonnes=2200*1*.01/1000

Tonnes=0.022

Therefore if you had a tonne of asphalt of density 2200kg/m³ and spread it to a thickness of 1cm, you would cover 45.45±m² (1/0.022)