42cal logo
42cal
MarathonOS

Run Your Next Marathon.

Free Training Tools

View all →

Pace Calculator

Calculate splits, finish time, and pace for any distance.

Race Time Predictor

Predict marathon, half, and 10K times from a recent race.

BQ Calculator

Check if your time qualifies for the Boston Marathon.

Training Pace Zones

Get your VDOT and five training zones from Jack Daniels.

Race Day Fuel Planner

Plan carbs, hydration, and electrolytes for race day.

Course Difficulty Analyzer

Score any course on elevation, altitude, heat, and more.

MarathonOS

Take your training further

Track runs, follow a plan, and prepare for race day with MarathonOS for iOS.

Download on the App Store
Scan to download MarathonOS

Scan to download

42Cal · MarathonOS

© 2025 42Cal. All rights reserved.

Tools

Your Race HistoryRace Time PredictorCompare RacesBQ CalculatorPace CalculatorTraining PacesDifficulty AnalyzerFuel PlannerAll tools

Explore

BlogLocationsDistancesCountries

Stay Updated

Weekly race tips + new race alerts

SupportPrivacyTermsFeedback: biz@42cal.com

    Featured Races

    Nov 8, 2026Marathon (26.2 miles / 42.2 km)
    The Lowdown

    The Marathon des Alpes-Maritimes Nice-Cannes is France's second-largest marathon by finishers and one of the most visually spectacular point-to-point courses in European road running. Starting on Nice's legendary Promenade des Anglais, the route traces 42 kilometers of uninterrupted Mediterranean coastline through the glamorous towns of Cagnes-sur-Mer, Antibes, Juan-les-Pins, and Golfe-Juan before finishing on Cannes' iconic Promenade de la Croisette. Roughly 95% of the course hugs the sea, offering breathtaking views of the turquoise Côte d'Azur at every turn. The profile is mostly flat with gentle undulations, making it a favorite among runners chasing fast times in a stunning setting. A World Athletics Label event and AIMS-certified course, it draws over 8,500 marathon finishers and nearly 60,000 spectators each November. One of the race's best perks: your bib doubles as a free train ticket for unlimited TER rail service between Nice and Cannes on race day, solving the point-to-point logistics beautifully. November's mild Riviera weather — typically 10-17°C — adds to the appeal of what many consider the most beautiful marathon route in France.

    Marathon des Alpes-Maritimes Nice-Cannes

    Nice, France

    Oct 19, 2026Marathon (26.2 miles / 42.2 km)
    7/10 CR

    TREK Antwerp Marathon

    Antwerp, Belgium

    Article

    Post-Marathon Blues: The Emotional Comedown After 26.2

    “The more I run, the more I love my body. Not because it's perfect, far from it, but because with every mile it is proving to me that I am capable of more than I ever thought possible.”

    — Unknown

    Nov 22, 2026Marathon (26.2 miles / 42.2 km)
    25K Runners

    Philadelphia Marathon

    Philadelphia, PA, United States

    Sep 27, 2026Marathon (26.2 miles / 42.2 km)
    -304m Downhill

    Loch Ness Marathon

    Inverness, Scotland, United Kingdom

    Nov 1, 2026Marathon (26.2 miles / 42.2 km)
    1.2K Runners

    City of Oaks Marathon

    Raleigh, NC, United States

    3K+
    Miles of Racing
    Ready to explore
    Nov 8, 2026Marathon (26.2 miles / 42.2 km)
    Mild Weather

    EDP Porto Marathon

    Porto, Portugal

    Article

    Valencia Marathon: Spain's Speed Factory for Personal Bests

    Nov 14, 2026Marathon (26.2 miles / 42.2 km)
    10K Runners

    New Zealand Sotheby's International Realty Queenstown Marathon

    Queenstown, New Zealand

    “Run when you can, walk if you have to, crawl if you must; just never give up.”

    — Dean Karnazes

    Oct 18, 2026Marathon (26.2 miles / 42.2 km)
    7/10 CR

    Ljubljana Marathon

    Ljubljana, Slovenia

    Oct 18, 2026Marathon (26.2 miles / 42.2 km)
    91m Elevation

    IMT Des Moines Marathon

    Des Moines, IA, United States

    Oct 18, 2026Marathon (26.2 miles / 42.2 km)
    The Lowdown

    The TCS Toronto Waterfront Marathon is an annual race in Toronto, Canada, featuring marathon, half marathon, and 5K events. Recognized as Canada's premier running event, it serves as the grand finale of the Canada Running Series and has hosted the Athletics Canada National Marathon Championships since 2017. The 2025 races are scheduled for October 18 (5K) and October 19 (marathon and half marathon). The event is committed to sustainability, achieving Evergreen Certification from the Council for Responsible Sport in 2023.

    TCS Toronto Waterfront Marathon

    Toronto, Ontario, Canada