Lactate Threshold Pace Estimator

LT pace ≈ pace you can hold for 60 min. Estimate from recent race or HR zone.

Inputs

Result

Loading calculator…
—

How to use this calculator

  • Pick base race.
  • Enter time.

About this calculator

Lactate threshold (LT) is the pace at which lactate accumulates faster than the body can clear — the "fastest pace you can hold for ~60 minutes." LT corresponds roughly to 80-85% max HR. Tempo runs at LT pace are the bread-and-butter of endurance training. Estimating: LT ≈ 5K pace + 30s/mi, 10K pace + 10s/mi, half-marathon pace.

Frequently asked

Why "threshold"?+
Below LT: lactate clears as fast as produced. Above: accumulates exponentially → fatigue.
Tempo run?+
Sustained 20-40 min at LT pace. Improves capacity at threshold; raises LT over time.
Training zones?+
Z1 easy < LT − 60s. Z2 endurance < LT − 30s. Z3 tempo = LT. Z4 threshold ≈ LT. Z5 VO2 max < LT.
Lactate test?+
Lab test: incremental treadmill with finger-stick lactate. True LT = 4 mmol/L or breakpoint. Field estimate within 5%.
Improves how fast?+
Tempo + intervals: ~5-8% LT pace improvement in 8-12 weeks for trained athletes.

Related calculators

VO2 Max from Cooper 12-Min Run
VO2max ≈ (distance in meters − 504.9) / 44.73. Cooper test estimates aerobic fitness.
Karvonen Heart Rate Zones Calculator
Target HR = ((max HR − resting HR) × intensity) + resting HR. The HRR (heart rate reserve) method.
Max Heart Rate by Age (4 formulas)
Compare Tanaka, Fox (220−age), Gulati (women), and Nes formulas for age-based max HR.
Race Time Predictor (Riegel formula)
Predict your time at any distance using Riegel's formula T₂ = T₁ × (D₂/D₁)^1.06.
5K Time Predictor (Riegel)
Predict 5K from another race using Riegel formula: T₂ = T₁ × (D₂/D₁)^1.06.
Training Load Acute:Chronic Ratio (ACWR)
AC:WR = 7-day training load / 28-day average. Sweet spot 0.8-1.3; >1.5 raises injury risk.

More tools you might like

Hand-picked tools that pair well with this one — same audience, same intent.

5K Time Predictor (Riegel)
Calc

Predict 5K from another race using Riegel formula: T₂ = T₁ × (D₂/D₁)^1.06.

Race Time Predictor (Riegel formula)
Calc

Predict your time at any distance using Riegel's formula T₂ = T₁ × (D₂/D₁)^1.06.

Karvonen Heart Rate Zones Calculator
Calc

Target HR = ((max HR − resting HR) × intensity) + resting HR. The HRR (heart rate reserve) method.

Max Heart Rate by Age (4 formulas)
Calc

Compare Tanaka, Fox (220−age), Gulati (women), and Nes formulas for age-based max HR.

Training Load Acute:Chronic Ratio (ACWR)
Calc

AC:WR = 7-day training load / 28-day average. Sweet spot 0.8-1.3; >1.5 raises injury risk.

Running Pace Calculator
Health

Pace, speed, and a full per-km and per-mile splits table for 5K / 10K / Half / Marathon at your entered pace. Toggle between km and miles for the input.