Mushroom Compost/Topsoil/Fill Dirt Bulk & Bagged Mushroom Compost / Topsoil / Fill Dirt Mushroom Compost Bulk does: 160 sf @ 2″ deep 40# bag does 3sf @ 2″ deep Topsoil Bulk does: 125 sf @ 2″ deep 40# bag does 3sf @ 2″ deep Fill Dirt Bulk Coverage: 125 sf @ 2″ deep