Calc how many liters in circle bath

Curious Geroge

I was hoping someone may be able to tell me how I can calculate how many liters of water are needed for a 1600 circle bathtub. Its approx 450mm deep to the drain. Have a 180lt cylinder in the hse and want to make sure it will fill the tub without risk.. thanks

invicta

Pie. times radius squared will give you capacity in gallons--if memory serves me

agusta

Curious Geroge wrote: »

I was hoping someone may be able to tell me how I can calculate how many liters of water are needed for a 1600 circle bathtub. Its approx 450mm deep to the drain. Have a 180lt cylinder in the hse and want to make sure it will fill the tub without risk.. thanks

Internal dimension of bath 1600mm - 1.6 metre, radius = 0.8 metre
Depth = height = h 450 mm - 0.4 metre

Formula = 3.14 x [ r x r ] h

3.14 x [ 0.8 x 0.8 ] .45

Answer = 0.9043 cubic metres

1000 litres in a cubic metre

1000 x 0.9043 = 904.3 litres

agusta

That calculation is based on a perfect circular bath filled from top to bottom with the dimensions you gave,in reality the bath diameter on the bottom is less.you must take into account that you will only be filling the bath just over half way,say 400 to 450 litres.The hot water is mixed with the cold water so in reality you will need maybe less than 300 litres.In my opinion a 180 litre cylinder is not big enough

seamus

The volume is always going to be a best guess since I assume there's also a curve in the bath wall.

But this calculator should be able to give you a very reasonable estimate:
http://keisan.casio.com/has10/SpecExec.cgi?id=system/2006/1223372110

Dtp1979

Use a weir gauge to see how many ltr/min is going into the bath. Then calculate how many mins to fill the bath.
Simple

wandererz

Fill the bath to your desired level and use a a bucket (e.g. a 10L litre paint bucket) to empty it out.

Time consuming but simples.

And it takes into account the variation in volume.

Do it before the water charges hit.