Need someone who gardens and/or is good with math

So, I can get 20kg of this stuff (planting gravel) for £16 if I order it today.  Melcourt Horticultural Gravel   My Prime membership expires today, and it'd cost a lot more (because of shipping) to wait until tomorrow, when I could contact the company to find out the answer to my question, below. I cannot lug it myself, so it needs delivering.

I was going to transplant my tomato plantlets into big pots, and add a two inch layer of this stuff on top of the soil to discourage fungus gnats. I have several other indoor plants that need a layer as well. For the life of me, I cannot figure out how much 20kg of gravel is in volume!  I don't want a huge bag that I could never actually use up delivered (nor do I want to pay for what I won't need). But I don't want to be paying 2/3rds as much for a quarter of the amount if buying a smaller bag, only to find out that the smaller bag isn't enough.

 I need enough to fill four pots with a diameter of 33cm about 5cm deep. And then the various other plants in the house with whatever is left. Say, the equivalent of two more 33cm pots, same depth.  The package says the gravel is "4-10 mm nominal particle size".

Any ideas how I can figure this one out?

So, I can get 20kg of this stuff (planting gravel) for £16 if I order it today.  Melcourt Horticultural Gravel   My Prime membership expires today, and it'd cost a lot more (because of shipping) to wait until tomorrow, when I could contact the company to find out the answer to my question, below. I cannot lug it myself, so it needs delivering.

I was going to transplant my tomato plantlets into big pots, and add a two inch layer of this stuff on top of the soil to discourage fungus gnats. I have several other indoor plants that need a layer as well. For the life of me, I cannot figure out how much 20kg of gravel is in volume!  I don't want a huge bag that I could never actually use up delivered (nor do I want to pay for what I won't need). But I don't want to be paying 2/3rds as much for a quarter of the amount if buying a smaller bag, only to find out that the smaller bag isn't enough.

 I need enough to fill four pots with a diameter of 33cm about 5cm deep. And then the various other plants in the house with whatever is left. Say, the equivalent of two more 33cm pots, same depth.  The package says the gravel is "4-10 mm nominal particle size".

Any ideas how I can figure this one out?

Try the customer questions and answers feature, you may hear back from someone who has bought it. If you go in through the reviews it's at the top of the page.

But you only need to spend £3.01 more on something else to make the £20 you need for free shipping without prime so maybe no need to rush the decision.

So, I can get 20kg of this stuff (planting gravel) for £16 if I order it today.  Melcourt Horticultural Gravel   My Prime membership expires today, and it'd cost a lot more (because of shipping) to wait until tomorrow, when I could contact the company to find out the answer to my question, below. I cannot lug it myself, so it needs delivering.

I was going to transplant my tomato plantlets into big pots, and add a two inch layer of this stuff on top of the soil to discourage fungus gnats. I have several other indoor plants that need a layer as well. For the life of me, I cannot figure out how much 20kg of gravel is in volume!  I don't want a huge bag that I could never actually use up delivered (nor do I want to pay for what I won't need). But I don't want to be paying 2/3rds as much for a quarter of the amount if buying a smaller bag, only to find out that the smaller bag isn't enough.

 I need enough to fill four pots with a diameter of 33cm about 5cm deep. And then the various other plants in the house with whatever is left. Say, the equivalent of two more 33cm pots, same depth.  The package says the gravel is "4-10 mm nominal particle size".

Any ideas how I can figure this one out?

Start here. Lots of calculators  online.

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Yeah, I did post a question to them....

And yeah, I guess I can find something else to buy to get over the free shipping limit. What's neat about prime is you can tell them what day to bring the stuff. So I don't have to sit at home waiting for ever, wondering when/if something is arriving that day. So if I order it today, it shows up tomorrow (or, preferably, Tuesday.) 

I found another kind of gravel, much smaller bits, that said for it it was 1.5k weight was about a litre of the crushed gravel. Since the pieces are smaller, they'd pack together closer, so a litre of it would probably weigh more than a litre of the stuff I was thinking of buying....? I'm thinking a litre per pot, so that's like four litres there. Which if it was the finer crushed stuff would be 6kg in weight. So a 20kg bag of this bigger stuff is probably way more than I need. I think. Maybe.

Some days I hate not being very good with math.  I do wish the vendors would say what the volume of the stuff is! If I knew how much was in the bag, I could sort out how much I need to buy!

Start here. Lots of calculators  online.

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The problem is, I don't know how much gravel is in 20kg.

So I know what I need as far as volume to fill the pots. But no idea how much that volume weighs, so how much to buy!~  They are selling it by weight, not volume.

Without knowing the dimensions of the bag, I'm not sure you can calculate the volume from the mass alone. 

Yeah, I did post a question to them....

And yeah, I guess I can find something else to buy to get over the free shipping limit. What's neat about prime is you can tell them what day to bring the stuff. So I don't have to sit at home waiting for ever, wondering when/if something is arriving that day. So if I order it today, it shows up tomorrow (or, preferably, Tuesday.) 

I found another kind of gravel, much smaller bits, that said for it it was 1.5k weight was about a litre of the crushed gravel. Since the pieces are smaller, they'd pack together closer, so a litre of it would probably weigh more than a litre of the stuff I was thinking of buying....? I'm thinking a litre per pot, so that's like four litres there. Which if it was the finer crushed stuff would be 6kg in weight. So a 20kg bag of this bigger stuff is probably way more than I need. I think. Maybe.

Some days I hate not being very good with math.  I do wish the vendors would say what the volume of the stuff is! If I knew how much was in the bag, I could sort out how much I need to buy!

Can you figure out the volume by the size of the bag?

And I pay for my Prime monthly.

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Here you go.

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Can you figure out the volume by the size of the bag?

And I pay for my Prime monthly.

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It doesn't even say the size of the bag! Just the weight! 

It doesn't even say the size of the bag! Just the weight! 

It does say.

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It doesn't even say the size of the bag! Just the weight! 

Here you go.

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Where did you find that???

Where did you find that???

Lol. It's just on the product information you posted a link to. Maybe it's easier for me to see it because I use the Amazon app.

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Ah. It doesn't show up at all on the webpage.
That's weird.

But problem solved, thanks!

If I need 17105cm per pot, and the bag only has 20300cm in it, it's tooo pricey. I'll go back to using sharp sand, instead, and just dress the very top with some pebbles.

Ah. It doesn't show up at all on the webpage.
That's weird.

But problem solved, thanks!

You're on your own to interpret that data. I am bad at math and converting metric to anything useful in my brain. I'm just good at Googling math calculators. Lolol

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