Getting the right size bum bag is crucial for both comfort and function. A bag that's too small frustrates with its limitations; one that's too large becomes cumbersome and uncomfortable. This comprehensive sizing guide will help you find the perfect fit for your body and carrying needs.
Understanding Bum Bag Measurements
When shopping for a bum bag, you'll encounter several measurements that affect fit and capacity. Understanding what each means helps you make informed decisions without relying solely on potentially misleading marketing terms like "compact" or "large."
Strap Length and Adjustability
The strap is arguably the most important sizing consideration. Most bum bags list a strap length range, such as "adjustable from 70cm to 130cm." This measurement typically refers to the total circumference when the strap is fastened, not the length of the strap alone.
To determine what strap length you need, measure around your body where you plan to wear the bag. For traditional waist wear, measure around your natural waist or hips, depending on your preference. For cross-body wear, measure from one shoulder diagonally across your torso to the opposite hip. Add a few centimetres for adjustment flexibility and to accommodate different clothing layers.
💡 Measurement Tip
When measuring for strap length, wear the clothing you'll typically have on when using the bag. A strap that fits perfectly over a t-shirt may be too short when you add a jacket. Most quality bum bags have ample adjustment range to accommodate seasonal clothing variations.
Bag Dimensions
Physical dimensions—length, height, and depth—tell you the actual size of the bag's main compartment. These measurements help you determine whether your essentials will fit. A bag measuring 25cm × 15cm × 8cm, for example, will comfortably fit most smartphones, a slim wallet, keys, and small personal items.
Pay particular attention to depth measurements if you plan to carry items like water bottles or larger smartphones. A shallow bag might fit your phone lying flat but not stand it upright, affecting how you organise your belongings.
Capacity in Litres
Many bags list capacity in litres, which indicates total storage volume. However, this measurement can be misleading—a 2-litre bag with multiple small pockets may hold less usable space than a 1.5-litre bag with one open main compartment. Use litre ratings as a rough guide rather than a definitive comparison.
To give you a practical reference point:
- Under 1 litre: Minimalist bags for phone, keys, and cards only.
- 1-2 litres: Standard everyday capacity; fits phone, wallet, keys, sunglasses, and a few small items.
- 2-3 litres: Generous capacity for those who carry more; room for a small water bottle, snacks, or camera.
- 3+ litres: Larger packs suitable for hiking, travel, or day trips where you need to carry more gear.
Measuring Yourself Correctly
Accurate body measurements ensure your bum bag fits comfortably in your preferred wearing position.
Waist Measurement
For traditional waist-level wear, measure around your torso at your natural waist—typically the narrowest part of your midsection, just above your belly button. Keep the measuring tape parallel to the floor and snug but not tight. This gives you the minimum strap circumference needed.
Hip Measurement
Many people prefer wearing bum bags lower, around the hips. Measure at the widest point of your hips, keeping the tape level. Hip measurements are typically larger than waist measurements, so if you might wear your bag in either position, use the hip measurement when selecting strap length.
Cross-Body Measurement
For cross-body wear, measure diagonally from your shoulder (where a bag strap would sit) across your chest to your opposite hip. This measurement is significantly larger than waist or hip measurements. Most adjustable bum bag straps accommodate cross-body wear for average-sized adults, but if you're particularly tall or broad, verify that the maximum strap length meets your cross-body measurement.
✅ Pro Tip
If you're between sizes or unsure, choose a bag with a wider adjustment range. It's better to have extra adjustment capacity you don't need than to find your bag uncomfortably tight or unable to accommodate different wearing positions.
Matching Capacity to Your Needs
Before selecting a size, honestly assess what you'll carry. Most people overestimate their needs initially, leading to bags that are larger than necessary. A too-large bag encourages overpacking, adds unnecessary weight, and can be less comfortable than a properly sized alternative.
Everyday Carry Assessment
Gather everything you'd typically carry in your bum bag. For most people, this includes:
- Phone (measure its dimensions if it's large)
- Wallet or card holder
- Keys
- Tissues or hand sanitiser
- Lip balm or small personal items
Measure this collection or fit it into a box to visualise the volume needed. You might be surprised how compact your essentials actually are when organised efficiently.
Activity-Specific Requirements
Different activities may require different bag sizes:
- Daily commuting: 1-2 litre capacity usually suffices.
- Travel: 1.5-2.5 litres allows for passport, documents, and extra security features.
- Running: Under 1 litre keeps weight minimal and bounce-free.
- Day hiking: 2-4 litres accommodates snacks, water, and emergency gear.
- Festivals: 1.5-2 litres balances capacity with security in crowds.
⚠️ Sizing Mistake to Avoid
Don't buy a larger bag "just in case." An oversized bag shifts more, is harder to keep organised, and tempts you to carry unnecessary weight. It's better to own two purpose-specific bags than one oversized compromise that works poorly for everything.
Size Considerations for Different Body Types
Your body type affects not just strap length needs but also which bag proportions look and feel best.
Petite Frames
If you're shorter or have a smaller frame, oversized bum bags can look disproportionate and feel awkward. Look for compact designs with streamlined profiles. Ensure the strap can tighten enough—some bags designed for larger sizes may not adjust small enough for petite wearers.
Larger Frames
Those with broader builds or larger waist measurements should verify maximum strap lengths carefully. Standard bum bags often max out around 120-130cm, which may be insufficient. Many brands now offer extended-strap versions, or you can purchase strap extenders separately for bags you already own.
Athletic Builds
Athletic bodies often have significant differences between waist and hip measurements. If this describes you, opt for bags with generous adjustment ranges that can accommodate both wearing positions comfortably.
Testing Fit Before Committing
Whenever possible, try on a bum bag before purchasing. When testing:
- Adjust the strap through its full range to ensure smooth operation.
- Load the bag with items similar to what you'll carry.
- Try different wearing positions—waist, hips, cross-body.
- Move around—walk, bend, sit—to identify any discomfort.
- Check that zippers and pockets are accessible while wearing.
Key Takeaway
The perfect bum bag fits your body comfortably across your preferred wearing positions and holds exactly what you need without excess bulk. Measure yourself accurately, assess your carrying needs honestly, and when in doubt, choose adjustability over assumptions. A well-fitted bum bag should feel like a natural extension of your outfit, not a bulky addition.
Quick Size Reference
Use these general guidelines as a starting point:
- Waist 65-85cm: Look for straps adjustable to at least 90cm minimum.
- Waist 85-100cm: Standard straps (70-130cm range) typically work well.
- Waist 100-120cm: Seek extended-length straps or strap extenders.
- Cross-body wear: Add 30-50cm to your waist measurement for required strap length.
Ready to find your perfect fit? Use our product comparison tool to filter by size and capacity, or take our style quiz for personalised recommendations.