Gradients

[Bellringer]

Is there a site where I can download a "ready reckoner" which converts gradients from percentages to the old fashioned 1 in 10 or 1 in 5 etc. I am too much of a dinosaur to be decimalised.

[Buenchico]

Express the gradient as a fraction (e.g. write '1 in 2' as ½) and multiply by 100.

Thus
1 in 2 = 50%
1 in 3 = 33%
1 in 4 = 25%
1 in 5 = 20%
1 in 6 = 17%
1 in 7 = 14%
1 in 8 = 13%
1 in 9 = 11%
1 in 10 = 10%
1 in 11 = 9%
1 in 12 = 8%
1 in 13 = 8%
1 in 14 = 7%
1 in 15 = 7%
1 in 16 = 6%
1 in 17 = 6%
1 in 18 = 6%
1 in 19 = 5%
1 in 20 = 5%
1 in 21 = 5%
1 in 22 = 5%
1 in 23 = 4%
1 in 24 = 4%
1 in 25 = 4%

The percentages given are rounded to the nearest whole number (which explains why some figures occur more than once). The table also assumes that '1 in 10' means a rise of 1 unit for every 10 units travelled horizontally. At one time some councils used that definition for their road signs whereas others used '1 in 10' to mean a rise of 1 unit for every 10 units travelled (along the hypotenuse of a right-angled triangle, instead of along its base).

Chris

[Hopkirk]

It would be easier if they just had agreed words.

Steep = 10%
Very steep = 17%
Bloody steep = 25%

Etc.

[Buenchico]

As a mathematics graduate, I prefer my answer.

As a motorist, I much prefer Hopkirk's answer ;-)

[Toureman]

Why don't they do it in degrees, now that would confuse most drivers but it would be accurate

[boxtops]

Am I right, that the gradient is based on the assumption that - e.g. 1 in 2 - means that for every two feet forward you travel, you go down one foot?

[espookid]

Boxtops you are a pessimist
why don't you go up two feet :-)

[factor-fiction]

^ yes, except in your example I think it can mean 2 up or 2 down

[boxtops]

O no I'm not - I like going uphill, I don't like driving down steep hills!

[boxtops]

Yes factor, you are right, I was only looking down!