Running Calculator

From race result toa complete training plan.

Turn one recent race result into a complete endurance training suite: Zone 2 and threshold targets, Norwegian 4×4 and Yasso 800s, race predictions, VDOT zones, and even-split pace bands.

Race pace
4:56 /km
01:44:00 benchmark
Max heart rate
184 bpm
134 bpm reserve
VO2 Max pace
4:26 /km
4 × 4-minute effort
Heart-rate map

Your training zones

Karvonen heart-rate reserve targets from recovery to VO₂ Max.

Based on the Tanaka maximum-heart-rate estimate (184 bpm) and your resting heart rate (50 bpm). Use breathing, perceived effort, and medical guidance when they disagree with an estimate.

Protocol 01

Zone 2 base

Build the engine. Keep the ego out.

Your easy target
6:19 /km
6 minutes 19 seconds per kilometer
130144 bpm · conversational effort
Keep your pace at or slower than this target. If your heart rate drifts above the range, slow down until your breathing settles.
Training tool

Treadmill converter

Convert your VO2 Max pace to speed.

VO2 Max effort
4:26 /km
Set a 1% incline to approximate outdoor air resistance.
Protocol 03

Norwegian 4 × 4

A simple, repeatable high-aerobic stimulus.

HardRecover
4 × hard effort
4:26 /km
90–95% max HR · 171177 bpm
3 × active recovery
3:00 easy
137146 bpm · jog or walk
Protocol 02

Cruise Intervals

Push your lactate threshold. 4 × 10-minute efforts.

Threshold target
4:50 /km
164169 bpm
4 × 10 mins hard · 2 mins easy recovery
Controlled discomfort is the goal: strong and repeatable, without sprinting or forcing the pace.
Protocol 04

Yasso 800s

Predictive marathon intervals. 10 × 800m.

800m interval target
3:37
03:36:50 predicted marathon
Active recovery jog: 3:37 easy
Ten 800m repetitions at this target are traditionally used as a marathon readiness benchmark, not a guarantee of race time.
Race prediction suite

Race Predictor

Riegel-based finish time and pace estimates from your baseline.

5K
00:22:36
4:31 /km
10K
00:47:08
4:43 /km
Half Marathon
01:43:59
4:56 /km
Full Marathon
03:36:48
5:08 /km
Even-split planning

Pace Band Generator

5:08 /km all the way to your predicted marathon finish.

KM mark
Cumulative time
5K
00:25:41
10K
00:51:23
15K
01:17:04
20K
01:42:46
Half
01:48:24
25K
02:08:27
30K
02:34:09
35K
02:59:50
40K
03:25:32
Finish
03:36:48
Daniels-style estimate

VDOT Training Zones

Estimated VDOT 43.1 with practical pace guidance.

ZonePace per kmPrimary purpose
Easy (E)5:58 /kmAerobic development and recovery
Marathon (M)5:09 /kmAerobic capacity and steady state
Threshold (T)4:46 /kmLactate threshold and steady state
Interval (I)4:24 /kmVO2 Max stimulus
Repetition (R)4:08 /kmRunning economy and speed
Performance context

Age-Graded Performance

A lightweight WMA-style comparison against an open-class standard.

Age grade
53.6%
Developing Benchmark
Age-graded time
01:40:53
Open-class equivalent
Age factor
0.970
Half Marathon standard

Age grading is an educational estimate using simplified age factors, not an official WMA result.

How it works

From one race result to a complete training plan.

Start with one recent race result, your age, and resting heart rate. The calculator uses that baseline to estimate what your current endurance can support across 5K, 10K, half-marathon, and marathon distances. It then turns the same result into a practical marathon pace band with cumulative checkpoints from 5K to the finish.

Next, use the VDOT-style zones to separate easy aerobic volume from Marathon, Threshold, Interval, and Repetition work. Heart-rate targets use the Karvonen heart-rate-reserve method, while maximum heart rate uses the Tanaka estimate. Age grading adds context across age groups using a simplified educational factor rather than an official ranking table.

The session cards translate those estimates into workouts: Zone 2 for your aerobic foundation, Cruise Intervals for controlled threshold work, Norwegian 4×4 for a high-aerobic VO2 Max stimulus, and Yasso 800s as a marathon-readiness benchmark. These are complementary tools, not four sessions to stack into one week. Keep easy days easy and place recovery between demanding workouts.

Worked application example: With a 1:44:00 half-marathon benchmark, the calculator estimates a marathon around 3:36:48, a 5:08/km marathon pace, VDOT near 43.1, a 6:19/km Zone 2 starting target, a 4:50/km threshold pace, and a 3:37 Yasso 800 target. Use these as connected planning references, then adjust for current training, terrain, weather, fueling, and how the session feels.

Runner’s FAQ

Questions about the endurance training suite.

What does the endurance training calculator generate?+

Enter a recent race distance and time, age, and resting heart rate to create a connected set of training references: race predictions, an even-split marathon pace band, VDOT-style training zones, age grading, Zone 2 and threshold targets, Norwegian 4×4, Yasso 800s, and treadmill speed.

How does Riegel's formula predict race times?+

Riegel's formula uses your baseline time and the ratio between the baseline and target distances: T2 = T1 × (D2 / D1)^1.06. The exponent makes predicted time rise slightly faster than distance, representing the additional fatigue of longer events. It is a useful comparison point, not a promise of performance.

How should I use the Pace Band Generator?+

Use the predicted marathon time to set even cumulative checkpoints from 5K through the finish. The band helps you control the early pace, monitor effort during the race, and make small adjustments for hills, heat, wind, aid stations, or fatigue without losing sight of the overall finish goal.

What does a VDOT score represent?+

VDOT is a performance-derived estimate of aerobic running ability from Jack Daniels' training framework. It converts a race result into practical Easy, Marathon, Threshold, Interval, and Repetition training paces. It is not a laboratory VO2 Max measurement, and the zones should be adjusted for conditions and recovery.

How does the Zone 2 target fit with the harder sessions?+

Zone 2 is the foundation: keep it conversational and use it for most weekly running. Cruise Intervals, Norwegian 4×4, and Yasso 800s are focused sessions with different purposes. They should be separated by easy or recovery days rather than stacked together as one workout.

What is the Norwegian 4×4 interval protocol?+

Norwegian 4×4 is four four-minute hard intervals near 90–95% of maximum heart rate, separated by three-minute active recoveries. It is a high-aerobic VO2 Max session. Treat the pace and heart-rate numbers as starting estimates and adjust for terrain, weather, fatigue, and experience.

How do Yasso 800s relate to marathon readiness?+

The Yasso heuristic turns the hours and minutes of a predicted marathon into the minutes and seconds of an 800m repetition. This calculator first applies Riegel's formula, then displays ten 800m targets with equal-time recovery. Completing the workout does not guarantee the predicted marathon time.

What do Cruise Intervals do?+

Cruise Intervals are controlled threshold efforts: four 10-minute repetitions with two-minute easy recoveries. They provide sustained work near lactate threshold without turning the session into a race, helping you practice holding a strong, repeatable pace and managing rising fatigue.

How are the heart-rate targets calculated?+

Maximum heart rate uses the Tanaka estimate, 208 minus 0.7 multiplied by age. Training ranges then use the Karvonen heart-rate-reserve method, which combines maximum and resting heart rate. If you have a tested maximum or your conditions change, use judgment rather than treating the estimate as exact.

How does age grading level the playing field?+

Age grading compares a result with an age-standard performance and expresses it as a percentage, making broad comparisons across age groups possible. This site uses a simplified educational approximation of age factors; use official WMA tables for formal rankings or competition results.

Are the calculator's paces exact?+

No. They are planning estimates derived from one race result and basic inputs. Fitness, terrain, temperature, wind, sleep, fueling, injury, and training specificity can all change the right pace. Use breathing, perceived effort, and heart rate as live checks during training.

Please read before training

Health and medical disclaimer

Health and Medical Disclaimer

The information, calculations, and training protocols provided by this website, including but not limited to pace estimates, heart-rate zones, and interval structures, are for educational and informational purposes only. They do not constitute medical advice, diagnosis, or treatment.

Always consult with a qualified healthcare professional or physician before beginning any new exercise program, especially high-intensity interval training (HIIT). If you experience faintness, dizziness, pain, or shortness of breath at any time while exercising, stop immediately and seek medical assistance.

Accuracy and assumption of risk

The physiological models used on this site, such as maximum-heart-rate formulas and aerobic-capacity estimates, are generalized mathematical models. They do not account for individual health conditions, environmental factors, or biomechanical differences. You acknowledge that running and high-intensity training carry inherent risks, including injury or death.

By using this tool, you assume 100% of the risk associated with using these calculations in your training.

Limitation of liability

Under no circumstances shall the creators, developers, or hosting providers of this website be held liable for any direct, indirect, incidental, or consequential damages, injuries, or health complications arising from your use of, or inability to use, the information and tools provided on this site. Use this tool entirely at your own risk.