Key points
- Weight is expressed in pounds (lb): from 6 lb (2.7 kg) up to a maximum of 16 lb (7.26 kg).
- The 10% of body weight rule is only a rough estimate: the real test is whether you can control your delivery.
- Four coverstock families: polyester (straight), urethane (gentle hook), reactive (strong hook), particle (very oily lanes).
- A ball drilled to fit your hand is easier to control than a house ball, and often lets you bowl with 1 to 2 pounds more.
- For a first ball of your own, an entry-level reactive (or a polyester ball if you throw straight) is the best choice.
What weight of ball should you choose?
Choose the heaviest ball you can swing naturally, without tensing your shoulder, for at least three games. A heavier ball is deflected less by the pins, but a ball that is too heavy makes you lose your line, shortens your swing and tires your wrist. Between the two, accuracy must always come first.
Balls are sold in pounds (lb), from 6 to 16 pounds; 16 pounds (7.26 kg) is the maximum weight allowed under the rules. The diameter, on the other hand, is practically the same for all approved balls: between 21.59 cm and 21.83 cm (8.500 to 8.595 inches).
You often hear that you should pick a ball weighing 10% of your body weight, capped at 16 pounds. It's a rough rule: it takes no account of arm strength, age, experience or drilling. A 90 kg adult isn't necessarily better off bowling with 16 pounds from day one, and an experienced 55 kg female bowler often uses a heavier ball than the rule suggests.
| Bowler profile | Recommended weight (lb) | Equivalent (kg) |
|---|---|---|
| Child aged 3 to 6 (often with a ramp) | 6 | 2.7 |
| Child aged 7 to 10 | 6 – 8 | 2.7 – 3.6 |
| Pre-teen aged 11 to 14 | 8 – 11 | 3.6 – 5.0 |
| Adult beginner with a slight build, senior | 9 – 11 | 4.1 – 5.0 |
| Adult beginner of average build | 11 – 13 | 5.0 – 5.9 |
| Athletic adult or regular bowler | 13 – 15 | 5.9 – 6.8 |
| Experienced bowler, competitor | 14 – 16 | 6.4 – 7.3 |
These ranges are only a guide. For children, see also bowling with kids.
The swing test
At the centre, pick up the ball with your arm straight down by your side and swing it back and forth two or three times. If your arm is pulled down, if you have to bend your elbow or if your shoulder dips, the ball is too heavy. If you can barely feel it and it shoots forward too quickly, try one pound more.
A house ball feels heavier than a ball of the same weight drilled for your hand: its holes are large and standard-sized, so you have to squeeze to hold it. With a custom drilling, many bowlers move up 1 to 2 pounds from their house-ball weight.
Polyester, urethane or reactive: which material?
The coverstock is the ball's outer shell; it determines how much the ball grips the lane and therefore how much it hooks. There are four main families.
| Coverstock | Grip and hook | Oil sensitivity | Who is it for? |
|---|---|---|---|
| Polyester (plastic) | Very low, almost straight path | Very low | Beginners who throw straight; spare ball for all levels |
| Urethane | Moderate, smooth and consistent hook | Low to medium | Bowlers starting to hook the ball; dry lanes or short patterns |
| Reactive resin (solid, pearl, hybrid) | Strong; solid reactive grips early, pearl skids further then hooks hard | High | Regular bowlers who hook the ball; the majority of balls sold |
| Particle (reactive loaded with particles) | Very strong, grips even in oil | High | Experienced bowlers on very oily lanes |
House balls in bowling centres are almost always polyester: tough, cheap and predictable. Reactive balls, which appeared in the 1990s, transformed the game by making much stronger hooks possible. To learn how the material interacts with oil, read bowling lane oil.
What does a ball's core do?
The core (or weight block) is the dense mass at the centre of the ball. Its shape affects how the ball rotates and how sharply it hooks.
- “Pancake” core: a simple disc just under the surface, typical of polyester balls. Minimal reaction.
- Symmetric core: a regular shape, giving a gradual, predictable reaction. Ideal for a first reactive ball.
- Asymmetric core: an irregular shape, giving a more angular reaction at the breakpoint. Better suited to experienced bowlers.
Spec sheets list two values. The RG (radius of gyration) measures how the mass is distributed: a low RG makes the ball start rolling earlier, a high RG lets it skid further. The differential indicates the flare potential, that is, the ball's ability to shift its axis of rotation and therefore to hook. The USBC limits RG to between 2.46 and 2.80 and the differential to a maximum of 0.060.
How does drilling work?
A new ball is sold without holes: it is drilled by a professional (at a pro shop) based on measurements of your hand. In Morocco, the Tamaris Bowling pro shop in Casablanca sells balls and drills them to measure. This is the most important step of the purchase. The technician measures the size of your thumb and fingers, the distance between thumb and fingers (the span) and the angles at which the holes are drilled.
| Grip type | Principle | Advantages | Who is it for? |
|---|---|---|---|
| Conventional | Fingers inserted up to the second knuckle | Secure feel, little rotation | Beginners, bowlers who throw straight, house balls |
| Fingertip | Fingers inserted up to the first knuckle | Longer span, much more rotation | Bowlers who hook the ball |
The technician also chooses where to place the holes relative to the core (the layout), which can make the hook happen earlier or later. For a first reactive ball, a balanced layout suited to an average bowler is better than an extreme setup. Drilling is usually charged on top of the price of the ball.
Avoid buying a second-hand ball that has already been drilled for someone else's hand. A thumb hole that is too tight or an unsuitable span leads to inconsistent releases and can injure your thumb or wrist.
How much should you budget for a ball?
Prices depend mainly on the material and the range. The figures below reflect prices commonly seen on the European market, excluding drilling; they are only a guide, and import costs can push them up.
| Range | Ball type | Indicative price (€) |
|---|---|---|
| Entry-level | Polyester | 60 – 120 |
| Entry-level | Urethane or symmetric reactive | 120 – 180 |
| Mid-range | Reactive, symmetric or asymmetric core | 170 – 230 |
| High-end | Reactive or particle, asymmetric core | 220 – 300 and up |
A high-end ball won't improve a beginner's score: its very strong reaction also amplifies mistakes. Your money is better spent on a good drilling job and a pair of bowling shoes.
Which first ball should you buy?
- You throw straight and bowl a few times a month: a polyester ball drilled for your hand. It will become your spare ball if you progress.
- You're starting to hook the ball: an entry-level reactive with a symmetric core and a fingertip drilling. See how to hook a bowling ball.
- You bowl in a league: a versatile reactive ball, then a polyester ball for spares; extra balls will come later, depending on the lane conditions you encounter.
In Morocco, the range available in specialist shops is limited, and many bowlers buy their ball abroad or online. Get advice from experienced bowlers before ordering: the ASBM (Association Sportive du Bowling Marocain, the Moroccan Bowling Sports Association), which runs a weekly league at the Megamall in Rabat, is a good point of contact. In the meantime, try house balls of different weights at the bowling centres in Morocco to find yours. For an overview of the gear, see bowling equipment.
Frequently asked questions
What weight of bowling ball should an adult use?
Most adult beginners bowl with 10 to 13 pounds (4.5 to 5.9 kg), and regular bowlers with 13 to 16 pounds. The right weight is the heaviest one you can control for three games without straining.
Is the 10% of body weight rule reliable?
No, it's a rough estimate. It takes no account of strength, age, experience or drilling; the swing test at the centre is more reliable.
What's the difference between a polyester ball and a reactive ball?
A polyester ball grips the lane very little and goes almost straight: it suits beginners and spares. A reactive ball grips much more and hooks strongly towards the pins when you throw it with a hook.
What is the maximum weight of a bowling ball?
The maximum weight allowed is 16 pounds, or 7.26 kg. There's no official minimum weight, but the house balls in bowling centres usually start at 6 pounds.
How much does a bowling ball cost?
As a rough guide, expect to pay about 60 to 120 euros for a polyester ball and 120 to 300 euros or more for a reactive ball, excluding drilling. In Morocco, import costs can push these prices up.
Should you have your ball custom-drilled?
Yes, a ball of your own should be drilled to the measurements of your hand. A good drilling job improves your release and consistency, and helps prevent thumb injuries.
Sources and references
