Runners spread across a city avenue during a marathon

Bay to Breakers

It is a historic costumed race, also offered as a 15K and as a team Centipede.

Prepare for Bay to Breakers

A plan built from your answers and your race date.

Bay to Breakers runs west across San Francisco, from the bay out to the Pacific surf. The course is urban and paved, threading through downtown neighborhoods before reaching the city's large green corridor and finishing near the coast. San Francisco's topography makes itself felt early, with short but genuinely steep climbing in the first part of the route.

The race is part of the city's sporting and civic fabric: it is a historic costumed event, and a large share of the field runs in fancy dress. Three options are on the program: the 12K, a 15K Breakers Bonus for anyone wanting extra distance, and the Centipede team format.

The formats

3 formats on the program.

Format	Distance
12K	7 mi
15K Breakers Bonus	9 mi
Centipede (équipe)	7 mi

Organizer information, checked on September 21, 2026 · baytobreakers.com

When to start

A build for this distance usually runs 10 to 16 weeks. Counted back from race day, that puts the start somewhere between January 18, 2027 and March 1, 2027.

These ranges are working conventions, not a research finding — no trial has compared plan lengths against each other. What matters more is that the plan was built for the weeks you actually have, rather than shrunk down from a longer one.

How to choose your start date

When to start

January 18, 2027

→ March 1, 2027

Worth reading before you enter

Races and distances 10K, half, marathon: what each one really asks They are all running. They are not the same event. What limits you, how long you need, and how the race falls apart — all three change with the distance. Read Races and distances The big marathons: what each one actually demands A marathon is 42.195 km everywhere. What changes is the profile, the crowd, the weather you are likely to get — and so what your training should emphasise. Read Training Eating and drinking: what’s proven, what isn’t This is where confident advice most often runs ahead of the evidence. Some of it is well tested. Some is opinion wearing a number. And one common habit can kill you. Read

Questions

What is the date of Bay to Breakers in 2027?

Bay to Breakers is run on Sunday, May 16, 2027 in San Francisco. Date published by the organizer, checked on September 21, 2026.

What distances does Bay to Breakers offer?

The main event is a 12K over 12 km. There is also a 15K Breakers Bonus covering 15 km, and the Centipede, a team format also run over 12 km across San Francisco.

Do you have to wear a costume at Bay to Breakers?

No, it is not required, but it is the race's signature: Bay to Breakers is a historic San Francisco costume run, and a large part of the field starts in some form of fancy dress.

Other races

This list keeps growing; it draws no line. A race that is missing is prepared for in exactly the same way.

New York · United StatesHalf marathon United Airlines NYC Half March 0975 km. It is traditionally held on the third Sunday in March and runs from Brooklyn into Manhattan. Washington · United StatesHalf marathon Credit Union Cherry Blossom Ten Mile Run Apr 4 The Cherry Blossom Ten Mile Run is staged in central Washington, DC, around the monuments and along the T Indianapolis · United StatesHalf marathon IU Health 500 Festival Mini-Marathon May 8 Its signature feature is a full lap of the Indianapolis Motor Speedway oval, run on the track itself. Your race is not here? Tell us about your race You can prepare for it all the same. Any race, anywhere, and even a goal without a race.

Your race is on the calendar. Your plan should be too.

Build my plan

Secure payment with Stripe. Then allow about 30 minutes for your profile, in several sittings if you like.