I don't know of any good correlation at all b'c of different shapes, b'c some fruits are heavier than others as in meatier,more tissue than juice, and some other variables.

My own definition of a cherry tomato is under two ounces, but some see up to 4 oz as being a cherry tomato, but that would be an exception IMO.

Beyond cherries I have no definition at all and I've grown well over 3,000 varieties.( smile)

Carolyn

Carolyn

Thank you, Carolyn!

Of course there is a direct corelation between the diameter of a tomato and its weight. But it is not linear.

If there is such a thing as a "perfectly spherical tomato" its volume in terms of its radius is ; (4/3) * pi *(r)^3, where "r" is half of the diameter. lets take an example. : A tomato is 4 inches in diameter. How much does it weight ?

-- First we calculate its volume in cubic inches, by the above mentioned formula. It comes out = 33.50 cu-in.
-- Now, that tomato is roughly 18.56 fl-oz. (by volume)

-- Assuming that tomato has the same specific gravity as water (or very close to it) then one fl-oz is equal to 1 ounce by weight.

A QUICK SHORT CUT:
weigh in oz = 0.29 (d)(d)(d) OR w(oz) = 0.29 *(d)^3

lets check with the example above ( weight of a tomato in 4 inches in diameter) " w = 0.29 x 4 x4 x4 = 18.56 oz-w

example two: TWO inch in diameter : w= 0.29 x 2 x 2 x 2= 2.32 oz-w

-------------------------------------
conversion: 1 cu-in = 0.554 us fl-oz

Yeah, right. After all that math the best you can get is a possible weight of 1 cu in of any tomato - which tells you nothing. Great in theory but not use in actual practice.

bcfromfl - go to any grocery store and take a measuring tape with you. Measure and weigh one of the cherry tomatoes, one of their paste tomatoes and one of their slicing tomatoes. You'll be amazed at the differences in weight. Diameter is irrelevant to a paste or heart shape tomato for example. So a 2" in diameter paste tomato will weight 3x the amount of a 2" cherry tomato.

The real problem is the way you choose to grade tomatoes - forget diameter and inches. Food is measured in weights, in ounces, not by diameters or inches. :) So a trip to the store and using their scale will give you a good mental picture for reference of what a 4-6 oz and an 8-10 oz tomato looks like.

Better yet, pick up an inexpensive kitchen scale.

Dave

If it helps at all, a large hen's egg weighs approximately 2 oz. That's what I use as a comparison for the smaller tomatoes.

Linda

Linda ! LOL ! A woman's answer, I understood !
(My name is Deborah)

If you read OP's question, it is about "co-relation" between diameter and weight, MAYBE JUST FOR APPROXIMATION !.

What I did was just that, an approximation.
FIRST we assumed a spherical tomato. In real world there are FEW tomatoes that are near perfect sphere. Just our mother planet Earth is not a pure sphere. Most tomatoes are more like ellipsoid.

The SECOND assumption we made was to take the specific gravity of tomato equal to 1. But as I researched, most red ripe tomatoes IN AVEREAGE have a specific gravity of 0.95.

In my prior approximation: we had : weigh in oz = 0.29 (d)(d)(d) OR w(oz) = 0.29 *(d)^3

Taking into account the ellipsoidality and the specific gravity, we can revise that estimate closer as:

weigh in oz = 0.20 (d)(d)(d) OR w(oz) = 0.29 *(d)^3
That is about 30% reduction. This is the biggest diameter.

Keep in mind that those who post tomato size (in diameter, circumference, weight) they give you just some rough numbers. eg, "has round red fruits 2 to 3" in diameter".

But if you are dead curious you can do this at home. You need a graduated container and a scale.First measure the volume by immersing it in water. Then weigh it. And also measure the diameter with a caliper or by any other way.
.

Thanks for your understanding Deborah.

I am mathematically challenged and have to think up ways to compensate (LOL).

Linda

Thank you all for your help. I was just trying to get a rough idea of size vs. weight so I could make some approximations of the various claims in the seed catalogs. I only consider beefsteaks, which aren't perfectly round, of course, but close enough for rough calculations.

I must say that I'm surprised my largest Big Beef hybrids, just barely 4" across, would perhaps be considered more than a pound! Maybe the flattened tops and bottoms significantly reduces the volume below a 4" sphere?

Dave's suggestion of using the grocery scales to measure some tomatoes is probably the best bet, although I can't recall how accurate those scales are. I'll have to take a look when I go on Friday.

Thanks again, everyone!

One of my favorite places to compare different varieties is The Sample Seed Shop's website (sampleseeds.com). Remy includes a photo for most of her varieties and many of them include a hand, plate, or kitchen scale for reference. That could be a good way to cross-check the varieties you're considering to see how big they might get.

Kathy

I'm on the metric system so whatever you use, whether it be inches or ounces, i'm confused all the same!

USDA Size Classification of Tomatoes

Small
1. from 2 1âÂÂ8 inches
2. to 2 9âÂÂ32 inches

Medium
1. from 2ü inches
2. to 2 17âÂÂ32 inches

Large
1. from 2ý inches
2. to 2 25âÂÂ32 inches

Extra Large
1. from 2þ inches

1. Will not pass through a round opening with this diameter when the tomato is held with its greatest diameter parallel to the plane of the opening.
2. Will pass through a round opening of this size; the tomato may be held in any position for the test.
The sizes of cherry tomatoes and pear-shaped tomatoes may simply be given in inches or centimeters.

ÃÂ

Linda, I'm mathematically dyslexic. If there is such a thing anyway. If there is, I am !

@ antipodean

Here is the conversion in metric verion( grams and centimeter)

w(g) = 0.5 *(d^3) ---- (( d= diameter in centimeters))

NOTES:
-- this is for tomatoes that are FAIRLY round not awkwardly lobed, flattened, cat faced, elongated.
BTW:
I bough some tomatoes from store today: did the measurements, checked their specific gravity. Compared the actual weight to the formula. It was right on the money.