How Many Miles Is a 5K / 10K / Half Marathon / Marathon?
Whether you're signing up for your first race or comparing your performance across different events, understanding common race distances in both kilometers and miles is essential.
While most races use metric distances (5K, 10K, marathon), many runners—especially in the US—think in miles. This can create confusion when planning training runs, setting pace goals, or simply understanding what you've signed up for.
Let's break down the exact distances for every major race format, from the 5K to ultramarathons.
Quick Answer: Common Race Distances
5K = 3.1 Miles
The 5K (5 kilometers) is one of the most popular race distances worldwide—perfect for beginners and seasoned runners alike.
Exact Distance:
- • 5 kilometers = 3.10686 miles
- • Commonly rounded to 3.1 miles
Why 5K is Popular:
- Achievable for beginners (typically 25-45 minutes)
- Great for testing speed and pushing pace
- Available almost every weekend in most cities
- Can be raced frequently without excessive recovery time
Typical Finish Times:
- • Beginners: 30-40 minutes
- • Intermediate: 25-30 minutes
- • Advanced: 20-25 minutes
- • Elite: Under 15 minutes (men) / Under 17 minutes (women)
10K = 6.2 Miles
The 10K doubles the 5K distance and represents a significant step up in both endurance and challenge.
Exact Distance:
- • 10 kilometers = 6.21371 miles
- • Commonly rounded to 6.2 miles
Why 10K is Unique:
- Sweet spot between speed and endurance
- Long enough to require pacing strategy
- Short enough to maintain relatively fast pace
- Popular corporate race and fun run distance
Typical Finish Times:
- • Beginners: 60-75 minutes
- • Intermediate: 50-60 minutes
- • Advanced: 40-50 minutes
- • Elite: Under 30 minutes (men) / Under 33 minutes (women)
Half Marathon = 13.1 Miles
The half marathon sits perfectly between the 10K and full marathon—challenging but achievable without the extreme training demands of 26.2 miles.
Exact Distance:
- • 21.0975 kilometers = 13.1094 miles
- • Commonly rounded to 13.1 miles
Why Half Marathon is Popular:
- Serious challenge without extreme commitment
- Requires dedicated training but manageable recovery
- Often more scenic routes than shorter races
- Gateway race to full marathon training
- Can be raced multiple times per year
Typical Finish Times:
- • Beginners: 2:15-2:45
- • Intermediate: 1:45-2:15
- • Advanced: 1:30-1:45
- • Elite: Under 1:05 (men) / Under 1:10 (women)
Marathon = 26.2 Miles
The marathon is the ultimate test of endurance for most runners—a bucket-list achievement that requires months of preparation.
Exact Distance:
- • 42.195 kilometers = 26.2188 miles
- • Commonly rounded to 26.2 miles
📖 Historical Note:
The marathon distance was standardized at 42.195 km (26.2 miles) at the 1908 London Olympics. The course was extended so the race would finish in front of the royal box at the Olympic Stadium.
Marathon Training Requirements:
- Typically 16-20 week training plan
- Peak weekly mileage: 40-70 miles
- Multiple 18-22 mile long runs
- Significant recovery time needed between attempts
Typical Finish Times:
- • First-timers: 4:30-5:30
- • Intermediate: 3:30-4:30
- • Advanced: 3:00-3:30
- • Elite: Under 2:10 (men) / Under 2:25 (women)
Other Common Race Distances
Beyond the classic distances, here are other popular race formats you might encounter:
1 Mile / 1600m
- • 1 mile = 1.609 kilometers
- • 1600 meters = 0.994 miles (approximately 1 mile)
- • Classic track distance, pure speed test
15K (9.3 Miles)
- • 15 kilometers = 9.32 miles
- • Less common but growing in popularity
- • Bridge between 10K and half marathon
20K (12.4 Miles)
- • 20 kilometers = 12.43 miles
- • Popular in some countries
- • Great half marathon tune-up race
30K (18.6 Miles)
- • 30 kilometers = 18.64 miles
- • Excellent marathon preparation race
- • Tests marathon pace and endurance
50K (31.1 Miles) - Ultramarathon
- • 50 kilometers = 31.07 miles
- • Shortest standard ultramarathon distance
- • 4.8 miles longer than a marathon
100K (62.1 Miles) - Ultramarathon
- • 100 kilometers = 62.14 miles
- • Elite ultramarathon distance
- • Requires extensive ultra training experience
100 Mile - Ultramarathon
- • 100 miles = 160.93 kilometers
- • Ultimate endurance challenge
- • Often run on trails with significant elevation
Complete Distance Conversion Table
Here's a comprehensive reference table for all major race distances:
| Race Name | Kilometers | Miles |
|---|---|---|
| 5K | 5 km | 3.1 mi |
| 10K | 10 km | 6.2 mi |
| 15K | 15 km | 9.3 mi |
| 10 Miles | 16.1 km | 10 mi |
| 20K | 20 km | 12.4 mi |
| Half Marathon | 21.1 km | 13.1 mi |
| 25K | 25 km | 15.5 mi |
| 30K | 30 km | 18.6 mi |
| Marathon | 42.2 km | 26.2 mi |
| 50K Ultra | 50 km | 31.1 mi |
| 50 Mile Ultra | 80.5 km | 50 mi |
| 100K Ultra | 100 km | 62.1 mi |
| 100 Mile Ultra | 161 km | 100 mi |
Using Distance Knowledge for Race Planning
Understanding exact race distances helps you plan better in several ways:
1. Pace Strategy
Knowing the exact distance allows you to calculate precise pace targets. For example, to run a 25-minute 5K, you need to maintain 8:03 min/mile or 5:00 min/km pace.
2. Training Runs
When your coach says "run 10K easy," you know that's 6.2 miles—helping you plan routes and time commitments accurately.
3. Realistic Goal Setting
Understanding the distance jump from a 5K (3.1 mi) to a 10K (6.2 mi) helps you set appropriate time goals and training timelines.
4. Comparing Performances
Knowing distances in both units helps you compare performances across races in different countries or events using different measurement systems.
The Conversion Formula
If you need to convert other distances between kilometers and miles, here's the formula:
Kilometers to Miles
Miles = Kilometers × 0.621371
Miles to Kilometers
Kilometers = Miles × 1.60934
Quick Mental Math Trick:
- • Kilometers to miles: Divide by 1.6 (or multiply by 0.6 for a rough estimate)
- • Miles to kilometers: Multiply by 1.6
Plan Your Race with Our Tools
Now that you know the distances, the next step is planning your pace strategy. Our pace-to-speed converter helps you calculate exactly what pace you need to hit your target finish time.
Whether you're training for a 5K or a marathon, use our calculator to convert between pace and speed, plan splits, and set realistic goals based on your current fitness level.
Calculate Your Race Pace →