Coffee-to-water ratio is the single biggest lever for strength, more influential than bean choice or even roast level, and it is also the easiest thing to fix once you know your starting point. The Specialty Coffee Association's general guideline is a "golden ratio" of roughly 1 to 2 grams of coffee per 30 to 36 grams (about 1 to 1.2 fluid ounces) of water, though this is explicitly described as a starting range to adjust from, not a fixed law.
For drip coffee and standard pour-over, a common practical starting point is about 15 to 17 grams of coffee per 250 milliliters (roughly 1 cup) of water, sometimes phrased as a ratio of 1 to 15 or 1 to 17 by weight. If that comes out too weak for your taste, move toward 1 to 14. If it is too strong, move toward 1 to 18.
French press generally wants a slightly stronger ratio than drip, since the metal filter lets more oils and fine particles through, giving a fuller body that can handle a bit more concentration, commonly around 1 to 12 to 1 to 15. Cold brew runs stronger still while steeping, typically 1 to 4 for a concentrate meant to be diluted before drinking, or 1 to 8 if you want something closer to ready-to-drink strength straight out of the jar, covered fully in our cold brew guide.
Espresso works on a completely different scale because so little water is involved. A standard double shot is typically built from about 18 to 20 grams of ground coffee producing 36 to 40 grams of liquid espresso, a ratio closer to 1 to 2, which is part of why espresso tastes so much more concentrated than any of the methods above despite starting from the same beans.
If you do not own a kitchen scale, weight-based ratios are still worth approximating with measuring spoons, roughly 2 tablespoons of ground coffee per 6 ounces of water is a reasonable starting point for drip coffee, though spoon measurements vary more than weight does because grind size changes how much a spoonful actually weighs. A cheap kitchen scale is genuinely one of the highest-value small upgrades you can make to home brewing, more useful in practice than a fancier grinder or kettle. Perfect Daily Grind's piece on brew ratios is worth reading alongside this for the reasoning behind the numbers.
Water temperature matters alongside ratio, though it gets less attention. Most brewing guides recommend somewhere around 90 to 96 degrees Celsius, just off a full boil, since water that is too hot can over-extract and taste harsh, while water that has cooled too much under-extracts into a flat, sour cup. If you do not have a temperature-controlled kettle, letting boiled water sit for roughly 30 seconds to a minute before pouring gets you into a reasonable range.
Once you land on a ratio you like for your usual bean and method, write it down somewhere you will actually see it again, a sticky note on the coffee canister works fine. Consistency, more than any single perfect ratio, is what makes your morning cup reliably good instead of a coin flip every time. James Hoffmann makes much the same argument, that repeatability beats chasing a perfect recipe you cannot hit twice.