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

    Oct 3, 2026Marathon (26.2 miles / 42.2 km)
    The Lowdown

    The Malmö Marathon is Sweden's newest city marathon and one of its flattest and fastest, reviving Malmö's marathon tradition after a nearly 40-year hiatus since the city's last marathon in 1986. The course starts and finishes at the Ribersborg recreation area along the Öresund strait, offering panoramic views of the iconic 8-kilometer Öresund Bridge connecting Sweden and Denmark. Runners loop through the coastal waterfront past Scandinavia's tallest building — Santiago Calatrava's twisting neo-futurist Turning Torso — and through the heart of the city past the 16th-century Malmö Castle, the grand Stortorget main square, and the lively Folkets Park, Sweden's oldest public park. With just 28 meters of total elevation gain across the entire course, the Malmö Marathon is purpose-built for speed and personal bests. The inaugural 2025 edition attracted enthusiastic crowds and established the race as a serious addition to the Scandinavian running calendar. AIMS certification means the course is Boston Qualifying eligible, and the race's progressive cancellation policy — allowing full refunds within 24 hours and affordable transfer and distance-change options — is notably runner-friendly. October's cool 6-12°C temperatures and the cosmopolitan atmosphere of Sweden's most multicultural city make this a compelling destination for runners looking for a flat, fast autumn marathon in Scandinavia.

    MALMÖ MARATHON

    Malmö, Sweden

    Oct 17, 2026Marathon (26.2 miles / 42.2 km)
    350ft Elevation

    Garmin Kansas City Marathon

    Kansas City, MO, United States

    Article

    Base Building for Spring Marathons: Your October-November Blueprint

    “The real purpose of running isn't to win a race; it's to test the limits of the human heart.”

    — Bill Bowerman

    Oct 25, 2026Marathon (26.2 miles / 42.2 km)
    120m Elevation

    Dresden Marathon

    Dresden, Germany

    Oct 4, 2026Marathon (26.2 miles / 42.2 km)
    Mild Weather

    Portland Marathon

    Portland, Oregon, United States

    Oct 25, 2026Marathon (26.2 miles / 42.2 km)
    7/10 CR

    Wizz Air Venice Marathon

    Venice, Italy

    3K+
    Miles of Racing
    Ready to explore
    Oct 18, 2026Marathon (26.2 miles / 42.2 km)
    Mild Weather

    IMT Des Moines Marathon

    Des Moines, IA, United States

    Article

    Training Load vs. Training Stress for Runners

    Nov 8, 2026Marathon (26.2 miles / 42.2 km)
    25m Elevation

    Maratona Di Ravenna Città D'Arte

    Ravenna, Italy

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

    — Dean Karnazes

    Nov 8, 2026Marathon (26.2 miles / 42.2 km)
    8/10 CR

    Marathon des Alpes-Maritimes Nice-Cannes

    Nice, France

    Oct 3, 2026Marathon (26.2 miles / 42.2 km)
    -792m Downhill

    St. George Marathon

    St. George, UT, United States

    Nov 14, 2026Marathon (26.2 miles / 42.2 km)
    The Lowdown

    The New Zealand Sotheby’s International Realty Queenstown Marathon is a long-established and celebrated autumn event in New Zealand’s adventure capital, first run in the 1990s and grown into one of the most scenic road marathons in the Southern Hemisphere. Held on 14 November 2026 with an 08:20 start, the race draws a mix of elite athletes, serious club runners, and international destination runners who come for both the competition and the spectacular surroundings. The event is steeped in local support and tourism-friendly organization, showcasing the region’s hospitality with expo events, community festivities, and post-race celebrations in central Queenstown. The course winds along pristine sections of Lake Wakatipu and through the picturesque Queenstown Gardens, with sweeping views of the Remarkables mountain range and the lake’s mirror-like waters providing constant visual rewards. Runners experience a varied route that combines flat, fast lakeside running with gentle rolling sections through parkland and quiet residential areas, making it both scenic and runnable for a wide range of abilities. Aid stations, enthusiastic roadside supporters, and live music at select points create a lively, festival-like atmosphere that blends the serious focus of marathon racing with Queenstown’s adventurous, celebratory spirit. The race course is AIMS/Athletics New Zealand certified and has historically been accepted as a Boston Marathon qualifying course, making it attractive for athletes chasing qualifying times as well as those pursuing personal bests or a memorable destination marathon. Overall, the Queenstown Marathon offers a world-class, well-supported race experience in one of New Zealand’s most iconic landscapes.

    New Zealand Sotheby's International Realty Queenstown Marathon

    Queenstown, New Zealand