It would be best to weigh yourself, then pick up the box and weigh you and the box. Subtract your weight. At the low end of most bathroom scales there is more inaccuracy and non-repeatability. Yes, you can weigh luggage with a regular scale as long as it has a high enough weight capacity.

Weighing yourself while holding your luggage on a standard home bathroom scale is a "good enough" estimate but is not perfectly accurate for 2026 airline standards. Most home scales are calibrated for a specific weight range (typically 100–250 lbs) and may have a margin of error of 1–3 lbs when calculating the difference between two readings. Additionally, how you hold the bag—whether you shift your center of gravity or lean—can slightly alter the digital sensor's reading. In 2026, with airlines becoming stricter about even a half-pound overage, this method can be risky. A more reliable and affordable alternative is a dedicated digital luggage scale, which hooks onto the handle and weighs the bag in isolation. These are calibrated specifically for the 0–100 lb range and provide a much more precise reading. If you must use a bathroom scale, weigh yourself three times and take the average, but always aim to be at least 2 lbs under the airline's limit to account for discrepancies with the airport's industrial scales.