How we calculate

Data

Every device and charger on this site comes from the manufacturer’s published specifications, or from the sources linked on its page. A record is only published once its key values are confirmed. Anything we can’t confirm is left out rather than guessed.

Power

USB Power Delivery chargers and devices agree on a power level. We take the lower of what the charger can supply and what the device accepts. Some devices only reach top speed with an extra protocol (PPS for most Samsung and Google phones, AVS for the newest iPhone Pro models); without it we use the device’s lower standard limit.

Charging times

Where the manufacturer states a fast-charge time (for example “50% in 30 minutes with a 70W adapter”), we scale from that figure. Otherwise we estimate from battery capacity and the agreed power. Times assume the device is idle; using it while charging makes it slower. We only show a time when we have one of these two bases.

Corrections

Spotted something wrong? Tell us and we’ll re-check the source and update the page.