# How to figure how much oil for mold.

Discussion in 'Lye-Based Soap Forum' started by Soapmaker Man, Mar 26, 2008.

1. Aug 5, 2014

### scotsman

#### Well-Known Member

Joined:
May 18, 2014
Messages:
202
136
I really want to download and try out this spreadsheet. **** my laptop for committing suicide. I really need to get a new one.

2. Aug 5, 2014

### LBussy

#### Well-Known Member

Joined:
Jun 28, 2014
Messages:
1,328
1,030
Location:
Kansas City, MO
3. Aug 5, 2014

### scotsman

#### Well-Known Member

Joined:
May 18, 2014
Messages:
202
136
Thank you for the link. I'll have to wait till I get a new comp though because on my iphone it's read-only

4. Aug 6, 2014

### Hazel

Joined:
Feb 1, 2009
Messages:
12,667
1,838
Location:
Ohio
Thank you, Lee! I'll have to play with this one.

I did find 54 ounces of oil without a water discount almost filled the 5 lb mold. I was a little disappointed because I wanted some to fill a little dragon mold. I used your new calculator and it came up with 61.77 oz. I'll have to try this amount but it won't be until the weekend.

5. Dec 11, 2014

### Tilia

#### Active Member

Joined:
Oct 8, 2014
Messages:
39
17
Location:
Belgium
I use metric measurements and everyone seems to agree on something around volume x .7 to calculate the amount of oils needed for a mold. So I tried using that twice now and end up with less soap than needed both times.

I used a tea-box with 2 compartments today with each compartment measuring 8 x 6.5 x 4.5 cm's. So multiplying those measurements by 2 and then by .692 I ended up with 323 grams of oils needed. While these molds are small I still ended up with the soap being over half a centimeter below the line I wanted it to reach.

For the recipe I used the standard water amount used in soapcalc of 38%. I that what makes a difference? Not sure on how to factor the water amount in the calculation.

6. Dec 11, 2014

### IrishLass

Joined:
Feb 12, 2008
Messages:
16,095
9,756
Location:
Right here, silly!
Yep- the water amount (and any other extra additives included) will have an effect on the level. I don't exactly know how to calculate those variables in, though. I just use the equation as a rough guide and then keep meticulous notes of the actual outcomes and adjust from there.

IrishLass

7. Feb 2, 2015

### Cactuslily

#### Well-Known Member

Joined:
Dec 29, 2014
Messages:
550
226
Location:
Southwest
Idk why I'm still struggling so much! I seem to have a mental block when figuring out what size mold to use for what recipe. For example I made a batch of soap using BB 10" mold. Per calculations, I got 38.5oz. It states on website it holds 50. I'm assuming the recipe given could have had more soap added to mold so that's the differance. If a recipe states it makes a2 lb batch, does that mean I can use my 2.5 mold? Why am I having such a hard time?! I'm feeling my age! Am I overcomplicating this? L x W x H x .40= ounces of oils needed. This doesn't account for water and additives, correct? I plugged in 50ounces to soap calc ( which is what BB states). My recipe came out with a total of 53.1 ounces not including FO. The original recipe held total of 43.8 ounces. Does that mean my recipe won't fit into a 50 mold? Am I even making sense? Uggh! Probably not.

8. Feb 3, 2015

### Saponista

#### Well-Known Member

Joined:
Dec 16, 2013
Messages:
2,116
1,314
Location:
Plymouth, Devon, UK
LxWxHx0.4 is the calculation you would use if you were using full water. So you would do that and the resulting value is the amount of oils you would put into soapcalc with full water to fill your mould. Any other additives on top of that will increase the volume further and overfill the mould. If you are using a water discount then you need to do a different calculation. If you put the amount of fragrance you want to use into soapcalc too, it will take it into account for you I think.

9. Jul 20, 2017

### TrishNZ

#### Well-Known Member

Joined:
Jul 16, 2017
Messages:
49
103
Location:
Auckland, New Zealand
Has anyone worked this out in metric?

10. Jul 20, 2017

### Kittish

#### Enthusiastic Newbie

Joined:
Jun 12, 2017
Messages:
1,365
1,384
Location:
High altitude desert in southern Nevada
Post #187 has the weight/volume ratios for water, oils, and solid fats given in both metric and imperial. It's kind of clunky to get there, but with that info, plus the measurements of your mold you should be able to come up with a fairly close answer.

Also, this is an old thread. Last post before ours were over two years ago (though I'll admit the info in the thread may well be handy to several of us new folks). Necro posting is kind of frowned on, overall. Much better to quote snips from the old thread you're referencing in a new thread.

TrishNZ likes this.
11. Jul 20, 2017

### TrishNZ

#### Well-Known Member

Joined:
Jul 16, 2017
Messages:
49
103
Location:
Auckland, New Zealand
Sorry I am new and just using the search feature. I am not sure what Necro posting is.

12. Jul 20, 2017

### Kittish

#### Enthusiastic Newbie

Joined:
Jun 12, 2017
Messages:
1,365
1,384
Location:
High altitude desert in southern Nevada
13. Jul 20, 2017

### Steve85569

#### Supporting Member

Joined:
Oct 28, 2015
Messages:
1,852
1,978
Location:
North East Oregon, USA
L x W x H = volume

Trish,

If you calculate in metric (cm) then multiply volume by 0.70 for the weight of oils that will fit.
If you calculate in inches use 0.37 for the weight of oils.

Some corrections will need to happen because of additives but this get me real close.

TrishNZ likes this.
14. Oct 15, 2017

#### Well-Known Member

Joined:
Jul 8, 2012
Messages:
1,296
681
Location:
Michigan
I realize this thread was started in 2008 but I'm hoping that someone can answer my question. I've seen this formula but with different numbers such as .40, .38 & the last post suggested .37. I don't care which number I use, I can't seem to get the right amount. When I've tried for example 7 * 3.75 * 3.5 * .40= 36.75 ounces (rounded up to 37) as the amount of oils, I end up with a few ounces of too much soap. So, reasoning that the formula calculates volume/how much the mold holds, I've tried creating recipes that have a total weight of 37 oz but I usually end up a few ounces shy of a full mold. Where am I going wrong?

15. Oct 15, 2017

### dibbles

#### Supporting MemberSupporting Member

Joined:
May 7, 2015
Messages:
5,408
5,031
Location:
Minnesota
Are you using a water discount? Using that formula, with full water, 31 ounces will fill my mold. At 30% lye concentration, 32 ounces will fill it, with maybe a bitty bit left over.

16. Oct 15, 2017

#### Well-Known Member

Joined:
Jul 8, 2012
Messages:
1,296
681
Location:
Michigan
I usually use full water, 38% and whatever lye concentration that soapcalc gives me. I made this mold & 1 other about 2 years ago & I don't think I've ever been able to correctly calculate how much soap batter I need.

17. Oct 15, 2017

### soaperwoman

#### Active Member

Joined:
Mar 3, 2017
Messages:
35
36
Location:
Sarasota, Florida
I know this may sound dumb but I hate math so all I do is fill my mold with water and then measure that to get my volume. Then I reverse engineer the water amount on a soap calc and oila! It isn't very scientific but it works every time.

Zany_in_CO likes this.
18. Oct 15, 2017

#### Well-Known Member

Joined:
Jul 8, 2012
Messages:
1,296
681
Location:
Michigan
I've done that with my silicone molds but this is a homemade wooden mold. It's not going to hold water.

19. Oct 15, 2017

### dibbles

#### Supporting MemberSupporting Member

Joined:
May 7, 2015
Messages:
5,408
5,031
Location:
Minnesota
Why don't you purposely make a little too much batter with your regular recipe/water amount and weigh what is left when your mold is full?

Millie, SaltedFig and Susie like this.
20. Oct 15, 2017

### Millie

#### Well-Known Member

Joined:
Dec 15, 2016
Messages:
789
808
If you are having good luck using that method, could you line your mold with a garbage bag for your water measurement?

Draft saved Draft deleted

Title
Replies Views
Last Message

Replies:
25,657
Views:
935,478

Replies:
8
Views:
252

Replies:
1
Views:
13

Replies:
36
Views:
1,279

Replies:
0
Views:
12