“hi snowbear, do washers have an automatic weight detection such that it will also control the water input and will only allow amount of water equivalent to weight of load.(+/- x%) . If there is none, what is the advisable weight to water ratio, assuming light type and heavy type of clothes/fabric?
Also, what is the advisable ratio of detergent / water / dry load assuming light type and heavy type clothes/fabric?” – naveen

“hi,
re weight detecting washer…there is none that i am familiar with. however, they have a load weight balance detector to make sure you are loading the tub properly where it will trigger an error when there is unbalance load.
anyway, most automatic washer -be it top or front or large load – operates with a water level sensor thus there is a selector where you can select what load level you want – small to large- but is actually a correlation to the water level the tub will be filled with water.
as a rule of thumb for top load, is to load the washer tub with garments only up to the water level. thus in my previous post, i have pointed that the garments should be just until the plastic rim because that is where the water will fill when the selector is set to large load. consequently, when light load is selected, all garments should be immersed in the filled water which is 1/2- 3/4 of the tub depending on washer model.
so since we are limited with the water level as well as the washer’s volume capacity, we can only approximate the ratios based on typical garments.
in a 10kg topload washer…
at large load selected, you can load about 5 kg dry. the washer will fill in around 25 li (25kg) of water during wash cycle
at small load seleted, the dry weight is around 3 kg. the washer will fill in around 15 li  (15kg) water.
thus the wash formula should be based on that ratio. different detergent suppliers will give different recommended dosages.  but for purpose of discussion basing on most commercial detergents (those found in supermarkets), dose required is about 1 scoop  (~30grams) per kg of garment for regular detergents and 2/3oz per kg of garments for hi-power detergents.
so in summary for 10kg topload,
ratio of clothes/water/detergent is :1kg/5li/1scoop
of course when we talk of other washer type, it will be another ratio.” -SNOWBEAR