To Scale Chains:
On 1″ = 400′ maps use the 60 scale and read directly in chains.
On 1″ = 100′ maps use the 30 scale and divide the scale reading by 2 to get the chain equivalent.
A quick way to calculate acreage:
Length x width = area
Area * .000023 = acres
This method is accurate to the fourth digit.
| 1 inch | .0833 feet |
| 7.92 inches | 1 link |
| 12 inches | 1 foot |
| 1 vara | approx. 33 inches |
| 2 3/4 feet | approx. 1 vara |
| 3 feet | 1 yard |
| 25 links | 16 1/2 feet |
| 25 links | 1 rod |
| 100 links | 1 chain |
| 16 1/2 ft. | 1 rod |
| 5 1/2 yards | 1 rod |
| 4 rods | 100 links |
| 66 feet | 1 chain |
| 80 chains | 1 mile |
| 320 rods | 1 mile |
| 5280 feet | 1 mile |
| 1760 yards | 1 mile |
9 sq. ft. = 1 sq. yard
30 1/4 sq. yds. = 1 sq. rod
16 sq. rods = 1 sq. chain
1 sq. rod = 272 1/4 sq. ft.
1 sq. ch. = 4356 sq. ft.
10 sq. chs. = 1 acre
160 sq. rods = 1 acre
4840 sq. yards = 1 acre
43560 sq. ft. = 1 acre
1 sq. acre = 208.71 ft. sq.
640 acres = 1 sq. mile
1 section = 1 sq. mile
1 Twp. = 36 sq. miles
1 Twp. = 6 miles sq.
1 inch = .0833 ft.
7.92 inches = 1 link
12 inches 1 foot
1 vara = approx. 33 inches
2 3/4 ft. = approx. 1 vara
3 feet = 1 yard
25 links = 16 1/2 ft.
25 links = 1 rod
100 links = 1 chain
16 1/2 ft. = 1 rod
5 1/2 yards = 1 rod
4 rods = 100 links
66 feet = 1 chain
80 chains 1 mile
320 rods = 1 mile
5280 feet = 1 mile
1760 yards = 1 mile
tan 0°0’1″ = 0/1000′ = .00485′
tan 0°01′ = 0/1000′ = .29089′
tan 1° = 0/1000′ = 17.45506′
