Yup:
I last used my sole surviving kitchen scale a couple days ago to research the relative weights of US 25 cent coins and US currency. For a Dope post … of course.
FYI 58 bills = 10 quarters. 
And yup again:
I used to have 2 identical scales: one in the office for mail weighing & one in the kitchen for food. The mail scale was back in the day when my late wife’s occupation included mailing multi-ounce first class paperwork almost daily.
That’s a long time ago.
I have to ask, why did you have to weigh your guinea pigs? Did you fatten them for eating later (just kidding 
)? I had guinea pigs myself, and of course you have to watch their condition, but I did that by look and feel, I couldn’t even tell you what’s the ideal weight for a guinea pig.
I have two, a digital scale and a spring scale. I use the digital scale for baking. I like to weigh flour and also sticky stuff, like lard or molasses, which i can slowly add to the flour until u hit the right weight, and not have to try to scrape them out of a measuring cup. I mostly use volume for less-sticky liquids. I use either for white sugar, whichever is more convenient in light of the rest of the recipe. I only use volume for brown sugar, the weight varies too much if it dries out a little.
I use the spring scale when i want to be able to hold a tare for a long time. It’s convenient to weigh the apples I’m preparing for apple pie (3 pounds is a little too much, but i like a generous apple pie) but it can take my much longer to peel and chop all those apples than the digital scale will stay on. I also use the spring scale to weigh kittens.
I think the poll results show a bias of, “people with kitchen scales are more likely to open this thread”.
Having a kitchen scale is really handy. Even if you do not use them much (which I do not since I do not bake much) it is just really nice to have one when need. They are cheap and most are pretty small and slim so easily slide into even crowded cabinets.
If you are someone who never bakes and rarely cooks anything more than a microwave dinner or frozen pizza then no…not needed.
American living in Europe. I bought one soon after moving to Europe, and then had to replace it when the battery died, because the battery wasn’t replaceable.
The second one has a replaceable battery. The store that I bought it in closed years ago.
I mostly use it for baking, but also for checking the weight of a letter or card. 20 grams or less is 2.50 CHF, more than 20 grams is 4.20 CHF, so it’s worth checking, and that way I don’t have to wait in line at the post office to weigh the letter.
If I don’t put enough postage, I’ll get a bill from the Post, but I prefer to avoid that.
American and yes. It’s primarily for baking, as accuracy matters for most baked goods, and as mentioned above, being able to zero out means fewer bowls to deal with.
American, and we usually use our scale for portion control.
We don’t cook much, and when we do, measuring cups seem sufficient for our needs. I think my daughter has a scale for sourdough or something.
American, and we use it often for baking. It’s also used often for ground beef - either portioning 5.33 oz for burgers or breaking it into 16 oz portions for freezing. Ours tares itself when it turns on, so I have a favorite wide mouth mixing bowl that fits perfectly, so it mostly gets used with the scale. That reduces the number of dirty dishes, as others have said.
I do use mine for baking. But it’s mostly for weighing my dogs’ dry food so I can manage their weight. Dry food weight seems to vary quite a bit between bags, and 3/4 cup is not very precise for roundish kibble.
I buy around five pounds of ground beef at a time. I use the scale to make one-pound portions, which are wrapped tightly in fold-top bags, put into a gallon-size zip-top bag with as much air as possible forced out, and stored in a freezer. I use the scale to make ¼-pound or 5-ounce patties for burgers. Since I mix two meatloafs at a time, I weigh them so that the one for cooking and the one for storing are the same weight.
Gotta admit, if i were portioning 5lbs of ground beef into 1 pound portions to freeze, I’d just eyeball it. Even though i have a couple of suitable scales.
I also portion my cat’s gabapentin by eye. We get large capsules from the vet, and i portion two capsules into 7 daily doses. That matters more than the quantity of meat, and i know I’m not precise, and also, i think it’s good enough. She’s certainly done a lot better since we started giving it to her.
American, good cook. I wing it. No need for a kitchen scale.
To be honest, I don’t remember. It was probably something recommended in a guinea pig book or website to make sure they weren’t gaining or losing too much weight.
We buy a lot of food in bulk and primarily use the scale to separate for vacuum-sealing and storage. Also, dividing and vacuum-sealing medical marijuana into smaller quantities to keep it fresh.
Only occasionally used for baking …
Lucy
I use the scale mostly for measuring out my coffee in the morning. It is also used for portioning Costco ground beef into 1lb packets for the freezer.
I endorse this.
We have an ancient spring scale which I hate, and a digital scale which I’m fine with. I only use it for a few recipes, but I like to use it when I’m dividing bread dough, for bagels or pizza crusts or similar things.
I use mine to portion ground beef, as has already been mentioned, but I also use it when I have a two pound bag of shrimp and want to get one pound out for a recipe.
We also use it to measure the snow pea and bean harvest from the garden.
Very seldom used for cooking.