How heavy should your dumbbells be? Why one pair is never the right weight for everything
Anna and Charlotte's gym maths: why curls, presses, rows and squats each need a different dumbbell weight, and how to know when to go heavier.
By Anna & Charlotte · MNU-Certified Nutritionists · Level 3 Personal Trainers
Published 21 October 2026
TL;DR
There is no single right dumbbell weight, because different exercises use different muscles and need different weights. Anna and Charlotte's gym maths puts it simply: the weight you can curl is probably too light to press, and the one you can row is probably too light for a hinge or a squat. Pick a weight for each exercise, and go up when it starts to feel easy.
Key takeaways
- One pair of dumbbells won't suit every exercise. A curl uses a small muscle, a squat or deadlift uses your legs, bottom and back together
- Anna and Charlotte's gym maths ladder runs curl, overhead press, row, RDL, squat, deadlift, each usually needing more weight than the last
- The ladder is a guide, not a formula. Limb length, mobility, technique, experience and injuries all change your own numbers
- The NHS test is useful: work to the point where you need a short rest before repeating
- When a weight that once challenged you feels easy, go up a little, or add a rep or two, and write it down
Most of us buy one pair of dumbbells and expect them to do everything. They can't, and that's one of the quietest reasons women get stuck with strength training.
Anna and Charlotte posted a short reel about it on 30 September. They called it gym maths, and it became their most-liked post by a long way. Here is the idea behind it, what the follow-up reel clarified, and how to work out your own weights.
Why does one pair of dumbbells never fit every exercise?
Because each exercise asks a different set of muscles to do the work.
Here is how Anna and Charlotte put it in the reel: "One pair of dumbbells probably shouldn't be the right weight for your entire workout." Then they walk down the ladder:
- If you can curl it, it's probably too light for an overhead press.
- If you can overhead press it, it's probably too light for rows.
- If you can row it, it's probably too light for RDLs (Romanian deadlifts).
- If you can RDL it, it's probably too light for squats.
- If you can squat it, it's probably too light for deadlifts.
Their summary: "Different muscles. Different movements. Different weights." A curl works your biceps. A squat or a deadlift uses your legs, bottom and back together, which are much bigger muscles that can move far more.
That is why a weight that feels hard on a curl can feel like nothing on a squat. If you've ever done a whole workout with the same pair and wondered why your legs felt fine, this is the reason.
Knowing what to do, how heavy to go and when to progress is another story.
Does the squat really have to be heavier than the RDL?
No, and Anna and Charlotte were clear about that in a follow-up reel on 13 October.
The squat versus RDL line caused the most controversy. Their reasoning for putting it in the ladder: a squat is a compound movement, with big contributions from the quads, glutes and hip adductors, while the hamstrings and core stabilise. An RDL is hip-dominant, mainly hamstrings and glutes, with little knee movement. So there's a theoretical argument that the squat has greater load potential.
Then the important part. In their words: "That doesn't automatically mean everyone should be able to squat more than they RDL." Limb proportions, biomechanics, squat depth, mobility, technique, training experience and injuries all change how much anyone can lift in each movement. And there's no universal scientific rule that your back squat must be heavier than your RDL.
So read the ladder as a guide, not a formula. It's there to encourage you to challenge yourself with appropriate weights and to understand progressive overload. Your own numbers are the ones that count.
How do you choose the right weight for each exercise?
Test each exercise separately, and let the last few reps tell you.
The NHS says strengthening activities should be done "to the point where you need a short rest before repeating the activity" (NHS physical activity guidelines for adults, checked 21 October 2026). That is a useful test. If you finish a set without feeling you needed a breather, the weight is probably too light for that exercise. If your technique falls apart before the set ends, it's too heavy.
A simple way to work through it:
Expect to own more than one pair of dumbbells, or a set with adjustable plates, as you progress. Your curl weight and your squat weight will drift apart, and that is how it should look.
When is it time to go heavier?
When the weight that once challenged you starts to feel easy.
Anna and Charlotte made this point in a post on 19 October: picking up the same 5kg dumbbells week after week doesn't automatically mean you're building muscle. Those weights might have challenged you when you started, but if they now feel easy, it's time to progress.
This is progressive overload in plain terms: asking a little more of your muscles than last time. The NHS says to "build up slowly and aim to gradually increase the repetitions of each exercise over time" (NHS strength exercises, checked 21 October 2026). A small jump is enough. Heavier weight is one way to do it, and an extra rep or two is another.
We cover how a whole week fits together in strength and conditioning for women over 40, and the case for starting at all in why strength training matters more after 40. If you're lifting through perimenopause, what actually helps with menopause exercise is the companion read. Worried about losing muscle as you get older? Have a look at muscle loss after 40.
What if you'd rather not work it all out yourself?
That is the gap Anna and Charlotte describe: you know you should be lifting, you may even have dumbbells at home, but knowing how heavy to go and when to progress is another story.
aceSTRONG is their 12-week strength programme for women in their 40s, 50s and beyond. You get three follow-along strength workouts a week, at home or in the gym, with guidance on how to progress your weights and a community of women doing it alongside you. It's £99 as a one-off payment. It is follow-along, so you train with the videos rather than in a live class.
If you have an injury or a health condition, speak to your GP before you start lifting.
Frequently asked
What weights should a 50 year old woman use?
It depends on the exercise, so there isn't one answer. A weight that works for a bicep curl will be too light for a squat or a deadlift, because those use much bigger muscles. Choose each weight by how the last few reps feel with good technique, and go up when they stop feeling like a challenge. If you have an injury or a health condition, check with your GP before you start.
How much weight should a 40 year old woman be able to lift?
There is no universal number. How much you can lift in each movement depends on your limb proportions, mobility, technique, training experience and any injuries, as well as your age. A better question is whether the weight you're using still challenges you, and whether it's heavier than it was a few weeks ago.
Are 2kg weights enough to tone arms?
A weight is enough while it still challenges you, and too light once it feels easy. Anna and Charlotte's point is that picking up the same light weights week after week doesn't automatically build muscle. If your set ends and you could comfortably have done plenty more, it's time to progress.
