DT is not twice as fast, and HT is not half speed
Standard Double Time uses 1.5x speed; standard Half Time uses 0.75x. Calculate effective BPM as original BPM multiplied by clock rate. A 180 BPM section becomes 270 BPM at 1.5x and 135 BPM at 0.75x. For a constant-rate 120-second section, duration becomes 80 seconds or 160 seconds respectively. These examples describe elapsed time, not an automatic PP multiplier or a guarantee of ranked eligibility.
Keep the exact rate, not just the mod name
When using a custom rate, write the actual value beside the mod acronym. Keep the difficulty ID, client, AR, OD and other changed settings in the same note. Example: original 180 BPM, rate 0.90x, effective 162 BPM, same difficulty and skin. For a map with tempo changes, apply the rate to each relevant section rather than treating one BPM label as a complete description of the map.
A slower section is not an aim-only experiment
Changing clock rate changes the time between objects and the real time available for reading and hitting them. It can make several demands easier at once. If a slowed attempt improves, that alone does not identify the original problem. Compare the cursor and input sequence to see what changed. Do not multiply the AR or OD number by the rate as if these difficulty settings were BPM; use the client's effective settings when available.
Practise below the target, then retest the target
Suggested exercise: take one baseline at 1.00x, then try the same troublesome section at a manageable lower rate while keeping its lead-in. Make a small set of attempts and record the first repeated error. Increase the rate only when the intended movement and rhythm remain repeatable; return to 1.00x for a check before ending. If the lower rate is clean but the target is unchanged, use an intermediate step or an easier section rather than counting the slowed score as the target result.
Why does my estimate or leaderboard result differ?
Compare every mod setting, not only the visible acronym, and ensure the calculator used the same difficulty and rate. Check current eligibility in the client instead of assuming that a displayed PP estimate promises submission or ranking. Keep practice attempts and submitted score targets distinguishable in your notes. The useful outcome is a repeatable change at the intended settings, not a larger number produced by changing the task.
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