Running9 min read

12 Week Half Marathon Training Plan Using Our Running Calculators

Complete 12-week half marathon training plan with integrated pace, calorie, and TSS calculators. Every workout optimized for your fitness level.

Ready to run a half marathon? This 12-week training plan uses our running calculators to give you personalized paces for every workout. Whether it's your first half or you're chasing a PR, this plan adapts to your fitness level.

Before You Start

Find Your Training Paces

Enter a recent 5K or 10K time into our Running Interval Pace Calculator to get:

  • Easy (E) Pace: For most runs
  • Marathon (M) Pace: For tempo portions
  • Threshold (T) Pace: For tempo runs
  • Interval (I) Pace: For speed work

Calculate Your Goal Pace

Use our Half Marathon Pace Calculator to find your goal race pace based on your target time.

Estimate Calorie Burn

Plan your nutrition using our Half Marathon Calorie Calculator.

Training Plan Overview

PhaseWeeksFocusWeekly Volume
Base1-4Build mileage, establish routine25-40 km
Build5-8Add quality work, increase long runs35-50 km
Peak9-11Race-specific training40-55 km
Taper12Rest and prepare25-35 km

Week-by-Week Training Plan

Phase 1: Base Building (Weeks 1-4)

Week 1 - Foundation

DayWorkoutDetails
MonRestFull recovery
TueEasy Run5 km at E pace
WedEasy Run6 km at E pace
ThuRest or Cross-trainSwimming, cycling, or rest
FriEasy Run5 km at E pace
SatLong Run10 km at E pace
SunRest or EasyOptional 3 km recovery

Weekly Total: 26-29 km

Week 2 - Building Consistency

DayWorkoutDetails
MonRest
TueEasy Run6 km at E pace
WedEasy Run + Strides6 km + 4×100m
ThuRest or Cross-train
FriEasy Run5 km at E pace
SatLong Run12 km at E pace
SunRecovery Run4 km very easy

Weekly Total: 33 km

Week 3 - Adding Volume

DayWorkoutDetails
MonRest
TueEasy Run7 km at E pace
WedFartlek6 km with 5×1 min faster
ThuRest or Cross-train
FriEasy Run6 km at E pace
SatLong Run14 km at E pace
SunRecovery Run4 km

Weekly Total: 37 km

Week 4 - Recovery Week

DayWorkoutDetails
MonRest
TueEasy Run5 km at E pace
WedEasy Run5 km at E pace
ThuRest
FriEasy Run4 km at E pace
SatLong Run10 km at E pace
SunRest

Weekly Total: 24 km

Phase 2: Build (Weeks 5-8)

Week 5 - Introducing Quality

DayWorkoutDetails
MonRest
TueTempo RunWU + 15 min at T pace + CD
WedEasy Run7 km at E pace
ThuEasy Run + Strides6 km + 6×100m
FriRest
SatLong Run15 km at E pace
SunRecovery Run5 km

Weekly Total: 40 km

Week 6 - Building Strength

DayWorkoutDetails
MonRest
TueIntervalsWU + 5×1000m at I pace (2 min rest) + CD
WedEasy Run7 km at E pace
ThuTempo RunWU + 20 min at T pace + CD
FriRest or Easy4 km
SatLong Run16 km at E pace
SunRecovery Run5 km

Weekly Total: 45 km

Week 7 - Race-Specific Work

DayWorkoutDetails
MonRest
TueTempo RunWU + 25 min at T pace + CD
WedEasy Run8 km at E pace
ThuIntervalsWU + 6×800m at I pace + CD
FriRest
SatLong Run18 km (last 5 km at M pace)
SunRecovery Run5 km

Weekly Total: 50 km

Week 8 - Recovery Week

DayWorkoutDetails
MonRest
TueEasy Run6 km at E pace
WedEasy Run + Strides6 km + 4×100m
ThuRest
FriEasy Run5 km at E pace
SatLong Run12 km at E pace
SunRest

Weekly Total: 29 km

Phase 3: Peak (Weeks 9-11)

Week 9 - Peak Training

DayWorkoutDetails
MonRest
TueTempo RunWU + 30 min at T pace + CD
WedEasy Run8 km at E pace
ThuIntervalsWU + 4×1200m at I pace (3 min rest) + CD
FriEasy Run5 km
SatLong Run19 km (8 km at half marathon pace)
SunRecovery Run6 km

Weekly Total: 53 km

Calculate your TSS for this week using our Running TSS Calculator.

Week 10 - Sharpening

DayWorkoutDetails
MonRest
TueRace Pace TempoWU + 6 km at half marathon pace + CD
WedEasy Run7 km at E pace
ThuIntervalsWU + 5×1000m at I pace (2 min rest) + CD
FriRest
SatLong Run20 km (10 km at half marathon pace)
SunRecovery Run5 km

Weekly Total: 52 km

Week 11 - Final Peak

DayWorkoutDetails
MonRest
TueTempo RunWU + 25 min at T pace + CD
WedEasy Run7 km at E pace
ThuSpeed WorkWU + 6×600m at R pace + CD
FriEasy Run5 km
SatLong Run16 km (last 6 km at half marathon pace)
SunRecovery Run5 km

Weekly Total: 48 km

Phase 4: Taper (Week 12)

Week 12 - Race Week

DayWorkoutDetails
MonRestComplete rest
TueEasy Run + Strides5 km + 4×100m
WedEasy Run4 km at E pace
ThuShakeout3 km very easy + 2×100m
FriRestPre-race rest
SatRestPrep for race
SunRACE DAYHalf Marathon!

Weekly Total: 12 km + race (33 km total)

Using Calculators Throughout Training

Before Each Long Run

For Tempo and Interval Workouts

Weekly Monitoring

  • Track TSS to ensure appropriate loading
  • Monitor progress with VO2 max estimates from tune-up races

Race Day Strategy

Pacing

Use our Pace to Half Marathon Time Calculator to create split targets:

  • Start 3-5 seconds/km slower than goal pace
  • Settle into goal pace by 3 km
  • Hold steady through 15 km
  • Push if feeling good in final 5 km

Fueling

Calculate your calorie burn and plan:

  • Pre-race: 300-400 cal breakfast, 2-3 hours before
  • During race: 1-2 gels (after 45-60 min)
  • Take gels with water at aid stations

Final Checklist

  • Pace band or watch set with goal splits
  • Familiar shoes and clothing
  • Gels practiced in training
  • Know the course profile

After the Race

Update Your Calculators

Enter your new half marathon time into:

What's Next?

Visit our Running Calculators hub for all our free running tools.

Disclaimer: Information provided by this site is for educational purposes only and is not intended to be a substitute for professional medical advice specific to the reader's particular situation. The information is not to be used for diagnosing or treating any health concerns you may have. The reader is advised to seek prompt professional medical advice from a doctor or other healthcare practitioner about any health question, symptom, treatment, disease, or medical condition.