Full name: firkin [butter, soap]
Category type: weight
Scale factor: 25.40117272
The SI base unit for mass is the kilogram.
The SI derived unit for weight or force is the newton.
1 kilogram is equal to 0.039368261104442 firkin.
Valid units must be of the weight type.
You can use this form to select from known units:
firkin to mercantile pound
firkin to quarter (ton) [US]
firkin to chin [Japan]
firkin to catty [Japan, Thailand]
firkin to tael [Japan]
firkin to pud [Russia]
firkin to atomic mass unit 
firkin to drachme
firkin to catti [Japan]
firkin to arroba [Portugal]