Time Under Tension Calculator
This time under tension calculator converts your tempo notation(like 3-1-2-0), reps, and sets into total TUT per set and per workout — then tells you whether your tempo is tuned for strength, hypertrophy, or muscular endurance.
Track tempo, sets, and reps together in Sleet to keep every workout consistent.
Tempo Training Calculator — Understanding Time Under Tension
Time under tension (TUT) is the total number of seconds a muscle spends working during a set. It's calculated by adding the four phases of a rep — eccentric, pause at the bottom, concentric, and pause at the top — then multiplying by your rep count. Two sets of 10 reps can have very different training effects depending purely on tempo.
TUT Ranges by Training Goal
Under 20 seconds per set suits pure strength work — heavy weight, low reps, fast concentric. 20–40 seconds is the widely cited hypertrophy sweet spot. 40–70 seconds shifts toward hypertrophy-endurance hybrid work. Above 70 seconds trains muscular endurance more than size or strength.
Why Tempo Notation Matters
Tempo notation like 3-1-2-0 removes ambiguity from a training plan — everyone lifting the same weight for the same reps can still have wildly different outcomes if one person rushes the eccentric and another controls it. Writing tempo down keeps your training consistent and repeatable.
Time Under Tension — Frequently Asked Questions
How do I calculate time under tension?
Add the seconds for eccentric, pause at bottom, concentric, and pause at top, then multiply by reps to get TUT per set. This calculator does that automatically.
What is a good time under tension for hypertrophy?
Roughly 20–40 seconds per set is the commonly cited sweet spot for muscle growth, though sets up to 60–70 seconds can still build muscle.
What does tempo notation like 3-1-2-0 mean?
Four numbers in seconds: eccentric, pause at bottom, concentric, pause at top. 3-1-2-0 means a 3-second lowering phase, 1-second pause, 2-second lift, and no pause at the top.
Does a slower eccentric tempo build more muscle?
A slower eccentric increases total time under tension and mechanical stress, which may improve hypertrophy signalling — but must be balanced against completing enough total volume.
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