BQ Readiness Calculator
Enter a recent race result to find out how close you are to a Boston qualifying time.
Your Recent Race
Tell us about your most recent effort to see how it translates to a marathon.
Hours
Minutes
Seconds
Your BQ Readiness
We predict your marathon finish, compare it with your age-group standard, and show your gap.
Methodology
How to read your BQ readiness result
This calculator estimates how a recent race performance may translate to the marathon distance, then compares that estimate with the Boston qualifying standard for your age group and division. It is most useful when your input race was recent, well paced, and run at an honest effort on a reasonably comparable course. Half marathon inputs are usually more reliable than 5K inputs because they ask the body to solve a problem closer to marathon endurance.
Non-marathon predictions use Riegel's formula, a common endurance projection model that assumes pace slows as distance increases. The formula cannot see your weekly mileage, fueling, long-run durability, injury history, heat tolerance, or whether your tune-up race was tactical. Treat the number as a planning signal rather than a promise.
Boston registration has also required a buffer faster than the published standard in many recent years. If the calculator says you are exactly on the standard, your next planning step should be to create a safer cushion. Many runners build race plans around beating the standard by several minutes, especially in competitive age groups or years with high demand. For the 2027 Boston Marathon, qualifier registration runs September 14-18, 2026.
What to do with the number
If you are ahead of your standard, protect that advantage by choosing a race that matches your strengths: flat if you thrive on rhythm, rolling if you handle changes well, or downhill only if your legs are ready for sustained eccentric load and your post-index cushion still works. Starting with registration for the 2027 Boston Marathon, the B.A.A. applies downhill indexing to certified courses with 1,500+ ft net elevation loss: +5:00 for 1,500-2,999 ft, +10:00 for 3,000-5,999 ft, and no Boston qualifying eligibility for 6,000+ ft. If you are behind, look at the gap in training-cycle terms instead of treating it as a verdict.
A small gap may be closed with better pacing, more consistent fueling, or a cooler race day. A larger gap usually calls for a longer build, stronger aerobic volume, or a tune-up race to confirm progress before committing to a peak marathon.
BQ readiness FAQ
Which race distance should I enter?
A half marathon is usually the best predictor because it is long enough to reflect endurance but short enough that many runners race it hard during a marathon build. Shorter races are useful but less precise.
Does this include the Boston cutoff?
The calculator compares you with the published qualifying standard. It does not predict the future registration cutoff or apply downhill-course indexing, so runners close to the standard should plan a cushion and verify the course profile.
Why can two runners with the same time differ?
Boston standards depend on age group and division. The same predicted marathon time may be comfortably under one standard and over another, which is why the age and division inputs matter.
How to turn readiness into a race plan
If the calculator shows a positive cushion, use it to choose a race where execution risk is low. That usually means a course profile you have practiced, a start time that avoids heat, and logistics that do not require a complicated race morning. If the calculator shows a gap, identify whether the gap is fitness, pacing, endurance, or race selection. A runner who fades late may need more durable long runs; a runner who opens too fast may need a stricter pace plan.
Recheck readiness after a tune-up race or major training block. The best use of this tool is not one dramatic prediction; it is a series of checkpoints that show whether your Boston attempt is becoming more realistic as race day approaches.