Plan on 15 to 25 Mbps sustained for one 4K stream and 5 to 8 Mbps for 1080p, then multiply by the number of screens live at once. Two 4K streams is close to 50 Mbps of steady demand, and that has to coexist with everything else on the connection during the evening. Sustained is the operative word: a speed test peaks for a few seconds, while a match runs for two hours. HEVC changes the math in your favor, needing roughly half the bitrate of H.264 for the same picture, so a well-encoded 4K feed can sit nearer 15 Mbps than 25.

A 4K panel is not the same as a 4K pipeline. The player has to decode HEVC in hardware, the app has to be current, and the HDMI path has to carry the resolution end to end. Older streaming sticks decode HEVC in software or not at all, which shows up as stutter that no amount of bandwidth fixes. Check three things in order: whether the device lists hardware HEVC support, whether your player app is on its current version, and whether the TV input is set to the higher-bandwidth HDMI mode many sets keep off by default. A device fault looks identical to a network fault until you separate them.

Honestly, not by the label on the listing. Two practical tests get you closer. First, look at fine texture in motion, such as crowd detail or grass, because upscaled 1080p loses definition there while native 4K holds it. Second, watch the bitrate behavior: a stream that never rises above the range you would expect from 1080p is unlikely to be carrying a genuine 4K image, whatever it is tagged as. Run both on content you know well. This is the area where marketing is loosest across the whole category, so give it the twenty minutes it deserves during a trial rather than trusting a badge.

Headroom disappears. At 5 to 8 Mbps a 1080p stream tolerates a wobbly connection; at 15 to 25 Mbps the same wobble becomes a freeze. Diagnose by scope before changing settings. One channel failing while others play is a source problem. A whole category failing together is server-side. Everything failing at once points at the line, the player or a stalled session. Switch away from a frozen channel and back: if it recovers instantly, the session stalled and bandwidth was never the cause. Some buffering is oversold capacity upstream, which no local setting repairs, and that is precisely why a published uptime figure is worth asking for.

At about 7 GB per hour, three hours of 4K a night is roughly 630 GB across a month from one screen alone. Many US home internet plans cap somewhere near 1.2 TB, so a household with two 4K viewers can approach that without noticing. Two levers help. Watching 1080p on secondary screens drops those to about 3 GB per hour, and HEVC content costs roughly half of the H.264 equivalent for the same picture. Check the cap on your own plan before assuming 4K everywhere is the right default, because overage charges are a real part of the cost of a 4K subscription.