Acres to Mẫu (Northern Vietnam): the quick answer
1 ac = 1.12413 mẫu-b
1 acre equals 1.12413 mẫu (northern Vietnam)
To convert acres to mẫu (northern Vietnam), multiply the value by 1.12413. To go the other way, multiply mẫu (northern Vietnam) by 0.889579 to get acres.