HOWTO - Convert Decimal Feet to Feet and Fractional Inches
Unit conversion foot survey convert units...
See also Topography and Project Units
0.01' = 0.003048 m
1/8" = 0.0104167'
1 mm = 0.03937" ~ 5/128" (4/128" = 1/32")
NOTE: Metric surveys usually show 3 decimals (1 mm), so they're 3x the precision of Imperial surveys (1/8"), but FFE is only shown to 2? (10 mm / 0.03'; ~1/3 the precision), see #4074.11 ADR.
DO NOT convert differences in elevations, instead convert elevations separately, then subtract to find the difference (or you may get different results depending on how the various values are rounded). For example: two buildings at FFE 281.7' and 281.58' would be 0.12' apart (1 7/16"), but they should be converted first (to 281' 8 3/8" & 281' 7") then subtracted to find the difference (which is 1 3/8" NOT 1 7/16") [example from #5462.10 AMR-CDC 5/4/21].
Rounded to the nearest 1/8" with four exceptions (to nearest 1/16"):
Decimal Feet to Inches | |
---|---|
0.00' | 0" |
0.01' | 0 1/8" |
0.02' | 0 1/4" |
0.03' | 0 3/8" |
0.04' | 0 1/2" |
0.05' | 0 5/8" |
0.06' | 0 3/4" |
0.07' | 0 7/8" |
0.08' | 1" |
0.09' | 1 1/8" |
0.10' | 1 1/4" |
0.11' | 1 3/8" |
0.12' | 1 7/16" |
0.13' | 1 1/2" |
0.14' | 1 5/8" |
0.15' | 1 3/4" |
0.16' | 1 7/8" |
0.17' | 2" |
0.18' | 2 1/8" |
0.19' | 2 1/4" |
0.20' | 2 3/8" |
0.21' | 2 1/2" |
0.22' | 2 5/8" |
0.23' | 2 3/4" |
0.24' | 2 7/8" |
0.25' | 3" |
0.26' | 3 1/8" |
0.27' | 3 1/4" |
0.28' | 3 3/8" |
0.29' | 3 1/2" |
0.30' | 3 5/8" |
0.31' | 3 3/4" |
0.32' | 3 7/8" |
0.33' | 4" |
0.34' | 4 1/8" |
0.35' | 4 1/4" |
0.36' | 4 3/8" |
0.37' | 4 7/16" |
0.38' | 4 1/2" |
0.39' | 4 5/8" |
0.40' | 4 3/4" |
0.41' | 4 7/8" |
0.42' | 5" |
0.43' | 5 1/8" |
0.44' | 5 1/4" |
0.45' | 5 3/8" |
0.46' | 5 1/2" |
0.47' | 5 5/8" |
0.48' | 5 3/4" |
0.49' | 5 7/8" |
0.50' | 6" |
0.51' | 6 1/8" |
0.52' | 6 1/4" |
0.53' | 6 3/8" |
0.54' | 6 1/2" |
0.55' | 6 5/8" |
0.56' | 6 3/4" |
0.57' | 6 7/8" |
0.58' | 7" |
0.59' | 7 1/8" |
0.60' | 7 1/4" |
0.61' | 7 3/8" |
0.62' | 7 7/16" |
0.63' | 7 1/2" |
0.64' | 7 5/8" |
0.65' | 7 3/4" |
0.66' | 7 7/8" |
0.67' | 8" |
0.68' | 8 1/8" |
0.69' | 8 1/4" |
0.70' | 8 3/8" |
0.71' | 8 1/2" |
0.72' | 8 5/8" |
0.73' | 8 3/4" |
0.74' | 8 7/8" |
0.75' | 9" |
0.76' | 9 1/8" |
0.77' | 9 1/4" |
0.78' | 9 3/8" |
0.79' | 9 1/2" |
0.80' | 9 5/8" |
0.81' | 9 3/4" |
0.82' | 9 7/8" |
0.83' | 10" |
0.84' | 10 1/8" |
0.85' | 10 1/4" |
0.86' | 10 3/8" |
0.87' | 10 7/16" |
0.88' | 10 1/2" |
0.89' | 10 5/8" |
0.90' | 10 3/4" |
0.91' | 10 7/8" |
0.92' | 11" |
0.93' | 11 1/8" |
0.94' | 11 1/4" |
0.95' | 11 3/8" |
0.96' | 11 1/2" |
0.97' | 11 5/8" |
0.98' | 11 3/4" |
0.99' | 11 7/8" |
At Every 1/4" | At Intermediate 1/8" | Other Decimal Feet (2nd decimal) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
' (rounded) | ' | " | ' (rounded) | ' | " | ' | " | ||||||
0.00 | 0 | 0 | 0.01 | 0.01041667 | 0.125 | ||||||||
0.02 | 0.0208333 | 0.25 | 0.03 | 0.03125 | 0.375 | ||||||||
0.04 | 0.04166667 | 0.5 | 0.05 | 0.0520833 | 0.625 | ||||||||
0.06 | 0.0625 | 0.75 | 0.07 | 0.07291667 | 0.875 | ||||||||
0.08 | 0.083333 | 1 | 0.09 | 0.09375 | 1.125 | ||||||||
0.10 | 0.1041667 | 1.25 | 0.11 | 0.114583 | 1.375 | 0.12 | 1.44 | = | 1 | 112.64 | /256" | ||
0.13 | 0.125 | 1.5 | 0.14 | 0.1354167 | 1.625 | 56.32 | /128" | ||||||
0.15 | 0.145833 | 1.75 | 0.16 | 0.15625 | 1.875 | 28.16 | /64" | ||||||
0.17 | 0.166667 | 2 | 0.18 | 0.177083 | 2.125 | 14.08 | /32" | ||||||
0.19 | 0.1875 | 2.25 | 0.20 | 0.1979167 | 2.375 | 1 | 7.04 | /16" | |||||
0.21 | 0.208333 | 2.5 | 0.22 | 0.21875 | 2.625 | 3.52 | /8" | ||||||
0.23 | 0.2291667 | 2.75 | 0.24 | 0.239583 | 2.875 | ||||||||
0.25 | 0.25 | 3 | 0.26 | 0.2604167 | 3.125 | ||||||||
0.27 | 0.270833 | 3.25 | 0.28 | 0.28125 | 3.375 | ||||||||
0.29 | 0.2916667 | 3.5 | 0.30 | 0.302083 | 3.625 | ||||||||
0.31 | 0.3125 | 3.75 | 0.32 | 0.3229167 | 3.875 | ||||||||
0.33 | 0.333333 | 4 | 0.34 | 0.34375 | 4.125 | ||||||||
0.35 | 0.3541667 | 4.25 | 0.36 | 0.364583 | 4.375 | 0.37 | 4.44 | = | 4 | 112.64 | /256" | ||
0.38 | 0.375 | 4.5 | 0.39 | 0.3854167 | 4.625 | 4 | 7 | /16" | |||||
0.40 | 0.395833 | 4.75 | 0.41 | 0.40625 | 4.875 | ||||||||
0.42 | 0.4166667 | 5 | 0.43 | 0.427083 | 5.125 | ||||||||
0.44 | 0.4375 | 5.25 | 0.45 | 0.4479167 | 5.375 | ||||||||
0.46 | 0.458333 | 5.5 | 0.47 | 0.46875 | 5.625 | ||||||||
0.48 | 0.4791667 | 5.75 | 0.49 | 0.489583 | 5.875 | ||||||||
0.50 | 0.5 | 6 | 0.51 | 0.5104167 | 6.125 | ||||||||
0.52 | 0.520833 | 6.25 | 0.53 | 0.53125 | 6.375 | ||||||||
0.54 | 0.5416667 | 6.5 | 0.55 | 0.552083 | 6.625 | ||||||||
0.56 | 0.5625 | 6.75 | 0.57 | 0.5729167 | 6.875 | ||||||||
0.58 | 0.583333 | 7 | 0.59 | 0.59375 | 7.125 | ||||||||
0.60 | 0.6041667 | 7.25 | 0.61 | 0.614583 | 7.375 | 0.62 | 7.44 | = | 7 | 112.64 | /256" | ||
0.63 | 0.625 | 7.5 | 0.64 | 0.6354167 | 7.625 | 7 | 7 | /16" | |||||
0.65 | 0.645833 | 7.75 | 0.66 | 0.65625 | 7.875 | ||||||||
0.67 | 0.666667 | 8 | 0.68 | 0.677083 | 8.125 | ||||||||
0.69 | 0.6875 | 8.25 | 0.70 | 0.6979167 | 8.375 | ||||||||
0.71 | 0.708333 | 8.5 | 0.72 | 0.71875 | 8.625 | ||||||||
0.73 | 0.7291667 | 8.75 | 0.74 | 0.739583 | 8.875 | ||||||||
0.75 | 0.75 | 9 | 0.76 | 0.7604167 | 9.125 | ||||||||
0.77 | 0.770833 | 9.25 | 0.78 | 0.78125 | 9.375 | ||||||||
0.79 | 0.7916667 | 9.5 | 0.80 | 0.802083 | 9.625 | ||||||||
0.81 | 0.8125 | 9.75 | 0.82 | 0.8229167 | 9.875 | ||||||||
0.83 | 0.83333 | 10 | 0.84 | 0.84375 | 10.125 | ||||||||
0.85 | 0.8541667 | 10.25 | 0.86 | 0.864583 | 10.375 | 0.87 | 10.44 | = | 10 | 112.64 | /256" | ||
0.88 | 0.875 | 10.5 | 0.89 | 0.8854167 | 10.625 | 10 | 7 | /16" | |||||
0.90 | 0.895833 | 10.75 | 0.91 | 0.90625 | 10.875 | ||||||||
0.92 | 0.9166667 | 11 | 0.93 | 0.927083 | 11.125 | ||||||||
0.94 | 0.9375 | 11.25 | 0.95 | 0.9479167 | 11.375 | ||||||||
0.96 | 0.958333 | 11.5 | 0.97 | 0.96875 | 11.625 | ||||||||
0.98 | 0.979167 | 11.75 | 0.99 | 0.989583 | 11.875 |
see also T:\Lionel\Decimal Feet Conversion Reference.xlsx