Can I Qualify for Boston Marathon with a 1:45 Half Marathon?
A 1:45 half marathon predicts a marathon finish time near 3:38, which is close to many Boston Marathon qualifying standards.
How to use this tool
- Enter known race distance, finish time — minutes and finish time — seconds in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your marathon time and the full breakdown beneath it.
Boston Qualifier hopefuls — see if your 1:45 half marathon time suggests you can hit your age-group BQ standard on race day.
Frequently asked questions
- How accurate is the Riegel formula?
- For distances within 2–3x of your reference race it is generally accurate within 5%. Accuracy decreases for very long extrapolations.
- What exponent should I use?
- The standard exponent is 1.06. Some calculators use 1.07 for ultra distances. This tool uses 1.06.