Exiter Apps


Pace Converter is used by runners to calculate VO2 and VO2Max, calories burned, recommended training paces, and estimated race times. These values are computed after entering any two of: speed or pace (in kph, mph, mins/km, or mins/mile), distance (in miles or kilometers), or time. Unit conversions for all entered values are automatically performed.

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VO2 (or oxygen consumption) is a measure of the volume of oxygen that is used by your body to convert the energy from the food you eat into the energy molecules, called adenosine triphosphate (ATP), that your body uses at the cellular level. VO2Max (or maximal oxygen consumption) is simply the maximum possible VO2 that a given person can achieve. VO2 and VO2Max are important in the context of exercise, because they are a measure of your body's ability to generate ATP, and ATP is the energy source that allows your muscles to continue working while you are exercising. Therefore, by definition, a VO2Max measurement is ultimately a measure of your cardiorespiratory fitness level.

Based on ACSM (American College of Sports Medicine) VO2 formula

ACSM Run: 3.5 + [speed (meters per minute) * 0.2] + [speed (meters per minute) * % grade * 0.9] = VO2 in ml/kg/min

Recent studies have shown that the ASCM formula tends to over-predict by approximately 14%. A more accurate formula has been determined as

VO2Max (ml/kg/min) = 58.443 - (0.215 * age) - (0.632 * BMI) - (68.639 * % grade) + (1.579 * time)

and this will be added to the app in due course.


During aerobic/endurance exercise, as your exercise intensity increases, so does your VO2. If you continue to increase your exercise intensity you will eventually reach a point of maximal exertion (i.e. you cannot work any harder than you already are). Your VO2 at this stage of maximal exertion is called your maximal oxygen consumption (VO2Max). It is the maximum volume of oxygen that your body is capable of consuming and converting to energy for your working muscles.

This value is used when determining the recommended training speeds for the entered data.

Calories Consumed

The estimated calories burned for this activity. This is based on the speed and distance as well as the runner's body weight. The formula is the ACSM (American College of Sports Medicine) metabolic calculation for caloric expenditure and uses the comnputed VO2 value for this activity:

(Calorics in kcals/minute) 5
= VO2 in L/minute
(VO2 in ml/kg/min) * (body mass) 1000
= VO2 in L/minute

Age Graded Results

Age grading takes your time and uses the world record time for your gender and age to produce a score (a percentage). This score allows you to compare your personal performance against other people's performances even though they might be a different age and a different gender to you - the higher the score the better the performance.

The scores can also be compared across different race distances - to allow you to, for example, compare a 5km time against a marathon. The concept behind age grades is similar to that of Purdy points.

Age Grades are calculated to allow rough comparisons between all runners, and should not be taken too seriously. For example, age grading makes no allowance for different weather conditions or the varying terrains of the courses.

The data tables used to compute age grading were developed by the World Association of Veteran Athletes (now World Masters Athletics) and were first published in 1989. The tables used here are based on those, but have been updated using data from Alan Jones (2010 update for female road records) and Howard Grubb (2006 updates). The raw data is available from the Running for Fitness website.

Training Data

Threshold/Tempo Training Pace

Threshold, tempo, or T-pace, running is one of the most productive types of training that distance runners can do. Training at this pace helps runners avoid overtraining and yields more satisfying workouts and better consistency.

The proper pace for T-pace running is about 83 to 88 percent of VO2-max, or 88 to 92 percent of vVO2-max or maximum heart rate.

You can establish your proper pace for threshold running fairly closely by running at a velocity that produces an elevated yet steady state of blood lactate accumulation. This pace is a little faster than a pace that you could maintain for two or more hours (marathon pace for most people) but slower than the pace you could maintain for 30 minutes (10K race pace for better runners). This pace is easy to discern because at the latter pace blood lactate continues to rise over the course of the run (that is, there's not a steady state of blood lactate accumulation). Also, at the former pace, blood lactate slowly drops after an initial rise or after any elevated lactate resulting from race surges (also not a steady state of blood lactate accumulation).

Most runners can figure that their threshold pace is equal to a pace they could race at for 50 to 60 minutes. In fact, for slower runners, threshold pace might actually be 10K race pace because they are taking nearly an hour to "race" this distance. Intensity of effort, not necessarily distance of running or racing, is what determines the degree of stress being put on the body's systems.

Remember that the purpose of the workout is to stress lactate-clearance capability, not to overstress that capability. You can refer to threshold training as "comfortably hard" running. It shouldn’t feel "hard," which is the pace of pure interval training.

You should do threshold runs no more than once a week, and they should make up no more than 10 to 15 per cent of your total training.

Steady Training Pace

Steady runs, or steady state runs as some literature refers to them, are a great way to build aerobic strength, which is the foundation for your best performances from 5K to the marathon.

Simply speaking, steady state runs are defined to be efforts that are about 20% faster than the long run pace. You will find different definitions of a "steady run pace" on the internet and from different coaches, which is fine. If it is a different pace than what is suggesting here, the benefits will be slightly different, so keep that in mind.

VO2 Max Training Pace

VO2-max training helps you improve your running economy and your racing sharpness. These sessions are sometimes called "intervals", and are most useful when you are preparing for a race of 5K to half-marathon. Here's an example of a good VO2-max workout: 6 x 800 metres at VO2-max pace with 4 to 6 minutes of recovery jogging between efforts.

You should do VO2-max workouts no more than once a week, and they should make up no more than 6 to 10 per cent of your total training. (When you run these workouts, you are running at or near 100 per cent of your maximum oxygen capacity, which scientists call VO2-max.)

Speed-form Training Pace

Speed-form workouts help you improve your running economy, form and leg speed. These are also interval sessions tailored to help you prepare for races of 800 metres to 5K. Here's an example of a good speed-form workout: 8 x 400 metres at speed-form pace with 3 to 4 minutes of recovery jogging between efforts.

You should do speed-form sessions no more than once a week, and they should make up no more than 4 to 8 per cent of your total training.

Long Run Training Pace

Long runs form the foundation of all marathon training programs. Long runs build everything from your confidence to your discipline to your fat-burning. So, even when you're not training for a specific marathon, it's a good idea to do at least one semi-long run a week. Because long runs are done at a relaxed pace, there's great latitude in how fast you actually run. In general, slower is better than faster.

Let your long runs be your slow runs, and save your legs for other days of the week when you might do tempo runs or maximum-oxygen runs. But there are a thousand theories about how to do long runs, none of which have yet been proven superior to the others. The important thing is building up the distance and training your body to keep going for 3, 4, 5 or however many hours it's going to take you.

Yasso 800s Training Pace

Yasso 800s are an invention of Runner's World US writer Bart Yasso, who has run more than 50 marathons and ultramarathons. They're simple: if you want to run a marathon in 2:45, 3:29 or 4:11, you should train to the point where you can run 10 repetitions of 800 metres in the same time: 2:45, 3:29 or 4:11. The only difference is that your marathon time is hours:minutes and your 800 time is minutes:seconds. Bart suggests doing Yasso 800s once a week as part of your marathon training.

Start with perhaps 4 x 800 and build up to 10 x 800. Between the 800s, take a recovery jog that lasts as long as your 800s. A good Yasso 800 workout: 6 x 800m at Yasso pace with recovery jogs between the 800s.

Race Predictions

Based on the time/distance entered, we can use some crazy formulas to predict approximate race times.

There are certain assumptions that have to be made when unsing these models:

  1. You've done appropriate training for the distance. Doing a 22-minute 5K today doesn't mean you can do a sub-4 marathon tomorrow. Obvious, really.
  2. The race terrain (paved, cross-contry, hills, etc) is roughly similar to the reference run.
  3. You don't have a natural significant bias towards either speed or endurance. Some people, no matter how much training they do, will always over-achieve at one end of the scale.
  4. The calculations become less accurate for times under three and a half minutes and over four hours.

Purdy Points Model

The Purdy point system is calculated from a table of running performances compiled in 1936 called the Portuguese scoring Tables. The table lists distance and velocity from 40 meters to 100,000 meters. These velocity measures are assumed to be maximum possible velocity in a straight line. These performances are arbitrarily given a Purdy point of 950.

World record times in 1970 have about 1035 Purdy points.

Times are calculated from the table (t=d/v) by linear interpolation. Additionally, a time factor for startup and running on a curve of a track is also added. This "standard calculated" time is used to generate the points given some performance time at the same distance.

P = A (
Ts Tp
- B)


  • P - is purdy points
  • Ts - Standard time from tables + time factor
  • Tp - Performance time to be compared
  • A, B - the scaling factors.

However A and B have to change for different distances. A sliding scale for A and B was found by comparing velocity at 3 miles and 100 meters at 950 and 1035 point performances. Purdy comes up with:

k = 0.0654 - 0.00258V
A =
85 k
B = 1 -
950 A

where V is the average velocity of Tp.

More information on Purdy points:

  • The original paper: Computer Generated Track Scoring Tables Medicine and Science in Sports Vol. 2, No.3 , pp 152-161 Fall 1970
  • Related Least Squares model for the running curve Research Quartely, 45:224-238 Oct. 1974

both by J.G. Purdy

The equations used here are from the C program kindly presented by Patrick Hoffman on Cross Country, Track, and Running Analysis.

Riegel Model

This formula used was originally devised by Pete Riegel, a research engineer and marathoner, and published in Runner's World many moons ago by Owen Anderson in 1997. It has stood the test of time since then and has been widely used.

The formula is T2 = T1 x (D2/D1)1.06 where T1 is the given time, D1 is the given distance, D2 is the distance to predict a time for, and T2 is the calculated time for D2.

Cameron Model

This formula used was originally devised by David F. Cameron, a statistician with A. C. Nielson (at the time) and a self-described track nut. This model is based on the top 10 times in the world at each distance, using them to compute comparable performances across distances. The speed vs. distance model works well for post-1945 records at 800m through 10k. From 1964 onward it also works well for the marathon and half-marathon.

The formula is described on Patrick Hoffman's page at UMass Lowell and is used as follows, with new_time and old_time being in seconds and new_dist and old_dist being in meters:

a = 13.49681 - (0.000030363 x old_dist ) +
835.7114 old_dist 0.7905
b = 13.49681 - (0.000030363 * new_dist) +
835.7114 new_dist0.7905
new_time =
old_time old_dist
a b
x new_dist

Race Pace Calculator

A tool for generating a detailed race pace. By entering the distance you intend to run and the target time, along with the number of intervals you want to split the race into, a set of paces can be calculated.

The plan selected for a race must match what you have trained for, and must match the course for the race. For example, if the first half of the race is all downhill and the second half all uphill, running a negative split race will be very difficult and a positive split pace plan would be a better choice.

Even Splits

Even splits means that each interval is run at the same speed so you never vary the pace during the entire race.

Negative Splits

A negative split pace plan means that you intended to run the second half of the race faster than the first half, and the first half is slowed accordingly.

Negative split paces are most common with elite runners, but work well for casual runners as well. A 2% negative split is the most common and is the default for the calculator. An analysis of 6 marathons covering 876,703 results for 754,851 runners revealed that "Overall, the data suggests that it's beneficial to have a split time that is close to even, with a slightly negative split possibly being optimal." and "[of] runners who tried both positive and negative splits, a slightly negative split is the most common best performance."

Positive Splits

The opposite of a negative split plan. The second half of the race is run slower than the first half. This would be appropriate for a race course where the second half of the race is more difficult than the first such as an uphill section or one with hidden tiger traps.

App Info
App Name Pace Converter
Current Version 2.4
Release Date November 30, 2014
Download Links Get it on Google Play Get it on the Amazon App Store
Recent Changes
  • Feature: Age graded results and predictions calculated
  • UI: Add more Android 5 cleanup and conversion.