Four ounces is 113.3980925 grams

Four ounces is 113.3980925 grams. One avoirdupois ounce is 28.349523125 grams by definition, so the answer is that factor taken four times, and no rounding is needed until you decide how many decimals to print.

Mass units stack in a tidy way from there. Four ounces is 0.25 pound, 1,750 grains, 64 drams, 0.1133980925 kilograms and 113,398.0925 milligrams. The grain matters in ammunition and archery, the dram survives on some supplement labels, and the milligram figure is what a laboratory balance would show.

The scale check is worth stating plainly. A kitchen scale reading 113 g is showing four ounces rounded to the nearest gram, and the true value is 0.398 g heavier. That gap sits inside the tolerance of every consumer scale sold, so it costs nothing in the kitchen and everything in a jewelry shop.

The pound is 0.45359237 kilograms, and the ounce follows

The ounce is not defined on its own. The 2026 edition of NIST Handbook 44 lists the avoirdupois pound in Appendix C as 0.45359237 kilograms exactly, and one pound is 16 ounces. Divide 453.59237 grams by 16 and the ounce is 28.349523125 grams, with nothing left over.

The same chain appears in NIST Special Publication 811, the Guide for the Use of the International System of Units, which prints the pound to kilogram factor and the grain at 64.79891 milligrams. Sixteen ounces to the pound and 7,000 grains to the pound are both fourteenth century conventions that survived decimalization because trade needed a fine unit that never changed.

Multiplying by four is the last step. Four ounces is 113.3980925 grams, and ten ounces is 283.49523125 grams. Every ounce figure on this site comes from the same single constant, so a page for 4 oz and a page for 10 oz cannot disagree.

Rounding is where mistakes enter. Printing 113 g on a butter wrapper is a legal declaration rounded to the nearest gram, and it is 0.35 percent light. Printing 113.4 g is rounded to the nearest tenth and is 0.0017 percent heavy. Neither matters for a cake, and both matter if you are costing a product by the gram at scale.

Four fluid ounces is 118.29411825 milliliters, not 113.4 grams

This is the distinction that ruins recipes and shipping forms. An ounce of mass measures how much matter is present. A fluid ounce measures how much space a liquid fills, and the US fluid ounce is 29.5735295625 milliliters exactly. Four fluid ounces is therefore 118.29411825 milliliters, which is a volume, not a mass.

Water ties the two together loosely. At 20 degrees Celsius water has a density of 0.9982 grams per milliliter, so 118.29411825 milliliters of water weighs 118.0812 grams. That is 4.683 grams more than 113.3980925 grams, a gap of 4.1 percent. In a cake that gap is invisible. In an espresso shot it is the difference between a 30 second pull and a 24 second one.

Read the label to see which one you have. Coffee bags, chocolate, butter, meat and parcel weights are mass, so 4 oz on those is 113.4 grams. Milk, cream, vanilla extract, perfume and paint are sold by volume, so 4 fl oz on those is 118.29 milliliters. A yogurt cup marked 4 oz is usually mass, because the net weight statement on food follows weight.

The reverse number is just as useful. A recipe that calls for 113.4 grams of water is asking for 3.8414 fluid ounces, which is 0.4802 US cup. Measuring that by eye in a jug marked in cups is how a bread dough ends up 5 grams wetter than planned.

A stick of butter, a cup of flour, a scoop of coffee

Butter is the cleanest case because the wrapper already does the math. A US stick is a quarter pound, which is 4 ounces, which is 113.3980925 grams. Manufacturers print 113 g on a US stick, and European blocks are cut to 250 g, which is 8.82 ounces. Four sticks, one pound, is 453.59237 grams, so a recipe written in grams and a recipe written in sticks agree to within a gram.

Flour is the case where the ounce misleads. The USDA FoodData Central entry for all-purpose flour puts one cup at 125 grams, so 113.3980925 grams is 0.9072 cup, which is 0.91 cup, or a cup less about one and a half tablespoons. Granulated sugar at 200 grams per cup gives 0.567 cup, and chocolate chips at 170 grams per cup give 0.667 cup, which is exactly two thirds of a cup. The same 4 ounces fills widely different volumes depending on the pantry item.

Coffee is sold by mass and brewed by ratio. A 4 ounce bag holds 113.3980925 grams of beans. At a 1 to 16 ratio, that dose needs 113.3980925 x 16 = 1,814.4 grams of water, which is 1.81 liters, or 61.3 fluid ounces. A 12 fluid ounce cup holds 354.9 milliliters, so the bag brews 5.1 cups at that strength, and a 1 to 15 ratio stretches it to 4.8.

Meat shrinks as it cooks, and the label weight is raw. Four ounces of raw ground beef is 113.4 grams, and after frying it weighs about 85 grams, a 25 percent loss that is mostly water. A recipe asking for 4 ounces of cooked beef therefore needs 151 grams raw, which is 5.33 ounces.

A 4 oz serving on a nutrition label

US nutrition labels carry two numbers for the same portion. Under 21 CFR 101.9 the serving size must be given in a household measure and in grams, so a label reads something like 4 oz (113 g). The household measure is for the cook and the gram figure is for the label, and the FDA Food Labeling Guide, issued in 2013 and current as of January 2025, walks through that layout page by page.

The paren figure is rounded to the nearest whole gram for a serving that size, so a 4 oz serving prints 113 g rather than 113.4 g. Comparing two brands by the gram means comparing rounded numbers, and a 0.5 gram rounding on a 113 gram serving is a 0.44 percent swing before any real difference enters.

Portion cost follows the same unit. At $9.60 per pound, four ounces costs $2.40, because 4 ounces is a quarter pound. At $21.16 per kilogram, the same 113.3980925 grams costs $2.40, which is the check that the two price tags agree. A store that prints $9.59 per pound and $21.20 per kilogram is quoting the same price to two decimal places.

Postage and parcels use ounces for small items and pounds above that line. A 4 ounce envelope is 0.25 pound, which is 113.4 grams, and a kitchen scale that reads in grams is more precise than a postal scale that reads in whole ounces for anything under a pound.

Troy ounces and carats weigh something else

Precious metals are sold in troy ounces, which are 31.1034768 grams and about 9.7 percent heavier than the avoirdupois ounce used for flour and parcels. Four troy ounces is 124.4139072 grams, while four avoirdupois ounces is 113.3980925 grams. The difference is 11.0158 grams, and it is the reason a bar marked 4 oz needs a close look at the small print.

The conversion between the two systems is a division. Four avoirdupois ounces is 3.6458333 troy ounces, so a 4 ounce bag of silver shot sold as avoirdupois is not four troy ounces of silver. At a silver price of $1.00 per gram, that 11 gram gap is $11 on a single small lot.

Carats are a purity measure for gemstones and a mass unit of 0.2 gram, and the two uses share a name. As mass, 113.3980925 grams is 566.990 carats, which is a 113 gram stone and not a thing that exists. A one carat diamond is 0.2 gram, which is 0.00705 ounce, so a ring set with five one carat stones holds one gram of diamond.

Pharmacies and laboratories avoid all of this by working in grams. A prescription written in grains, at 64.79891 milligrams each, is a historical unit, and 1,750 grains is exactly 4 ounces only because the grain and the pound were fixed together.

The grain survives where precision is sold by the piece. Four ounces of powder is 1,750 grains, and a handgun charge of 5.0 grains per round stretches that to 350 rounds. A 150 grain rifle bullet leaves 11.67 bullets from the same 4 ounces, which is why reloaders buy powder in one pound jugs of 7,000 grains instead of by the ounce. Arrow builders weigh points the same way, and a 125 grain field point is 8.10 grams.

Reading grams back as ounces on a scale

The reverse direction is one division by 28.349523125, and it is the one that catches people out because kitchen scales in the United States default to ounces with one decimal place. One hundred grams is 3.5273962 ounces, so a 100 g portion reads 3.5 oz on that scale. The display has thrown away 0.027 ounce, which is 0.77 gram.

Two worked examples show the drift. A recipe calls for 250 grams of flour, and the scale is set to ounces: 250 / 28.349523125 = 8.8184905, so the display shows 8.8 oz and the cook adds 8.8 ounces, which is 249.5 grams, half a gram light. A parcel limit of 4 ounces is met by 113.3980925 grams, so a kitchen scale reading 113 g is under the limit by 0.398 gram and a scale reading 114 g is over it by 0.602 gram.

Rounding rules differ by trade, which is why the same 4 ounces appears as 113 g on a butter wrapper, 113.4 g in a metric recipe and 113.398 g in a laboratory note. Pick the precision that matches the job and stay with it through the whole recipe, because mixing 113 g and 113.4 g across six ingredients moves the total by 2.4 grams.

A conversion table is the fastest fix on the counter. One ounce is 28.35 grams, two ounces is 56.70 grams, three ounces is 85.05 grams, four ounces is 113.40 grams, and eight ounces is 226.80 grams. Halving and doubling from those anchors keeps the arithmetic inside your head.

A four ounce bar of soap and a candle pour

Soap and candles come in four ounce units because the number fits a mold and a label. A 4 ounce bar of cold process soap is 113.3980925 grams, and a 1 kilogram batch of oils yields 8.8 bars of that size once the water leaves during cure. A 4 ounce candle tin holds about 113.4 grams of wax, and wax at 0.86 grams per milliliter means the tin needs 131.9 milliliters of melted wax, which is 4.46 fluid ounces.

Fragrance load decides the rest of the recipe. At 6 percent by weight, 113.3980925 grams of wax takes 6.80 grams of fragrance oil, which is 0.24 ounce. At 9 percent it takes 10.21 grams. A scale reading to 0.01 gram is the right tool here, and on a pour this small a 0.5 gram slip is 0.44 percent of the batch.

Yarn follows the same habit. A skein marked 4 ounces is 113.4 grams, while a 100 gram skein is 3.53 ounces, so the two labels describe nearly the same ball of wool with a 13.4 gram gap that matters when a pattern gives yardage by weight.