Five milliliters is exactly one standard teaspoon, making it one of the easiest small volumes to measure without a syringe. Whether you’re dosing liquid medicine, mixing a supplement, or following a recipe, several household tools can get you to 5ml with reasonable accuracy. That said, the method you choose matters more than you might expect, especially if you’re measuring medication.
The Teaspoon Conversion
The simplest substitute is a proper measuring teaspoon from a kitchen measuring spoon set. One level teaspoon equals 5ml. This is the flat, standardized kind that comes on a ring with other measuring spoons, not a spoon you’d stir your coffee with. Fill it to the brim without letting it mound over the top, and you have your 5ml.
If you only have a tablespoon measuring spoon, one tablespoon equals 15ml, so you’d need one-third of a tablespoon. That’s harder to eyeball accurately, so a teaspoon is the better choice when available.
Use a Kitchen Scale for Precision
A digital kitchen scale is surprisingly effective for measuring small liquid volumes. Water and most water-based liquids (juice, liquid medicine, saline) weigh almost exactly 1 gram per milliliter. So 5ml of water weighs 5 grams.
Place your cup or container on the scale, zero it out (the “tare” button), then slowly add liquid until you reach 5 grams. Most kitchen scales are accurate to 1 gram, which means your measurement will be within about 1ml of the target. For thicker liquids like honey or syrup, this still works well, though the weight-to-volume ratio shifts slightly. For everyday purposes, treating 5 grams as 5ml is reliable enough for anything water-based.
Medicine Cups and Dosing Caps
Many liquid medications come with a small plastic dosing cup built into the cap. These typically have markings at 5ml, 10ml, 15ml, and 30ml. If you’ve lost the cup from one bottle, check other medicine bottles around the house. The cups are interchangeable as long as you wash them between uses.
Some cough syrup and cold medicine caps are themselves designed to hold a standard dose. Check the markings on the inside or outside of the cap before assuming its volume.
Bottle Caps as a Rough Guide
A standard plastic bottle cap from a water or soda bottle holds roughly 7ml when filled to the brim. Filling it about two-thirds full gets you close to 5ml. This isn’t precise, but it works in a pinch for non-critical measurements like mixing a cleaning solution or adding flavoring to food. Don’t rely on this method for medication.
Why Kitchen Spoons Are Unreliable
The spoons in your silverware drawer are not the same as measuring spoons, and the difference is bigger than most people realize. Kitchen spoons vary widely in size and shape. A decorative teaspoon might hold 3ml; a deep soup spoon labeled as a “teaspoon” in the set might hold 7ml. There’s no standard.
An NIH-funded study found that using a teaspoon or tablespoon from the kitchen to give children medicine doubled parents’ chances of giving an incorrect dose. Nearly 40 percent of parents in the study measured the wrong amount. Parents who thought about doses in teaspoon terms rather than milliliters were also far more likely to reach for a kitchen spoon, with 30 percent of them using one compared to just 1 percent of parents who thought in milliliters.
The American Academy of Pediatrics has recommended against using kitchen spoons for medication since 1975. Both the FDA and CDC now advocate for milliliter-only dosing on medication labels, partly because teaspoon terminology nudges people toward grabbing whatever spoon is in the drawer. In one study, parents who saw “teaspoon” on a prescription label had over four times the odds of choosing a kitchen spoon to measure the dose.
Getting a Syringe for Next Time
If you’re measuring medicine regularly, especially for a child, it’s worth picking up an oral syringe. Most pharmacies carry them for under a dollar, and pharmacists will often hand you one for free if you ask at the counter. Oral syringes have clear milliliter markings and eliminate the guesswork entirely. They’re particularly useful for doses smaller than 5ml, where even a proper measuring teaspoon becomes hard to use accurately.
Quick Reference for 5ml
- Measuring teaspoon: 1 level teaspoon = 5ml (most practical option)
- Kitchen scale: 5 grams of water-based liquid = 5ml
- Medicine dosing cup: Fill to the 5ml line (check markings carefully at eye level)
- Plastic bottle cap: About two-thirds full (rough estimate only)
- Kitchen spoon: Unreliable, varies from 3ml to 7ml depending on the spoon
For cooking or household mixing, a measuring teaspoon or kitchen scale will serve you well. For medication, especially for children, a proper measuring spoon or dosing cup is the minimum. The few seconds it takes to find the right tool can be the difference between an accurate dose and one that’s off by 40 percent or more.