Find out how much your cup holds
Recipes written for a cup become clearer when you know your own mug's working volume, with room left for leaves and comfortable handling.
Measure the fill you actually use
A mug advertised as holding 400 millilitres may reach that figure only when filled almost to the rim. That is not necessarily the amount you want beside your keyboard or on a tray. Before adjusting a tea recipe, fill the empty mug with cool drinking water to your usual comfortable level. Pour this into a measuring jug and read the volume at eye level on a flat surface.
This small measurement can explain a persistent weak cup. A tea bag recommended for 200 millilitres is being asked to flavour much more water in a generously filled oversized mug. Letting it stand longer may change the balance rather than recreate the intended cup. Reducing the water is a straightforward comparison to try before changing brands or adding several more minutes.
Allow for what goes inside
An infuser, a bulky portion of leaves and a splash of milk all take up space. Measure the water used for brewing separately from additions made later. For a removable basket, the working fill should immerse the leaves while leaving enough clearance to lift the basket without overflowing. Do not assume that filling to the rim gives a more generous or better extraction.
If you use a kitchen scale instead of a jug, place the dry mug on it, tare the display and add room-temperature water. For an ordinary household estimate, a gram of this water is close enough to a millilitre. This shortcut is for water, not a conversion between grams and millilitres of dry tea. Stay within the scale's load limit and do the measuring before anything becomes hot.
Keep one useful number
Write down the working water volume rather than the manufacturer's maximum capacity. You might discover that your everyday fill is 280 millilitres, even though the mug is sold as a larger size. Use that number when scaling a recipe, then let taste guide small adjustments. There is no need to measure every morning once you recognise the fill line. Recheck when you change mugs, because a similar-looking vessel can hold a noticeably different amount.
