The SPF edit: our summer essentials

Sun cream used to be something you packed for holidays and forgot about the rest of the year. That's changed. Dermatologists agree daily SPF is the most effective anti-ageing step in any routine, ahead of any serum or retinol. UV rays get through cloud and windows, so a grey day in March still counts. The good news is that modern formulas are light enough to forget you're wearing them.

What the numbers mean

SPF measures protection from UVB, the rays that burn. SPF 30 blocks about 97 percent, SPF 50 around 98. The star rating on UK packaging, from one to five, shows UVA protection, which covers the rays that age skin. Look for SPF 30 or above with four or five stars, or the UVA logo in a circle. Then use enough of it. Most people apply about a third of what they need.

Mineral or chemical

Mineral filters like zinc oxide sit on top of the skin and reflect light. They're gentle, which makes them good for sensitive skin, but some leave a cast on deeper skin tones. Chemical filters absorb UV and tend to feel lighter and blend more easily. Neither is better. The right one is the one that suits your skin and that you'll put on every morning.

Best for everyday

Ultra Violette Queen Screen is the cult favourite for good reason, with a light serum texture that sits well under make-up. La Roche-Posay Anthelios UVMune 400 is the dermatologist pick and easy to find at Boots. For something cheaper, Garnier Ambre Solaire Super UV is excellent and costs less than a meal deal.

Best for deeper skin tones

Black Girl Sunscreen makes formulas designed to disappear on deeper skin with no grey or purple tinge. Supergoop Unseen Sunscreen is completely clear and doubles as a primer. Both are worth trying if you gave up on SPF because of the cast.

Best for oily and acne-prone skin

Look for oil-free and non-comedogenic on the label. Beauty of Joseon Relief Sun, available at Cult Beauty, is a fan favourite with a light, almost watery feel. Paula's Choice and Bioderma both make matte formulas that keep shine down through the afternoon. Avoid heavy creams that sit on the skin and can clog pores.

Topping up over make-up

SPF wears off, especially if you're outside or sweating. Reapply every two hours in strong sun. Over make-up that's tricky, so use a mist or a stick. Shiseido and Supergoop both do clear sticks that slide over foundation without moving it. A powder SPF is useful for a quick top-up on the train home.

Don't forget the extras

Ears, neck, the backs of hands and the top of the chest show sun damage first, and they're usually the bits people skip. Use a lip balm with SPF, since lips burn easily. Wear sunglasses that block UV, and a hat on properly hot days. Scalps burn too, especially along a parting.

What about SPF in foundation?

SPF in make-up is a nice extra but not enough on its own. To get the stated protection you'd need far more foundation than anyone actually wears. Treat it as a bonus layer on top of your sun cream, not a replacement.

Make it a habit

Keep sun cream next to the toothbrush so it becomes part of the morning. Put one in your bag and one at your desk. Apply it after moisturiser and before make-up, and give it a minute to settle. Once it's automatic you'll stop thinking about it, and your skin will thank you in ten years.

Our edit below picks out the SPFs our editors rate most, from cheap and cheerful to the formulas worth paying a bit more for.

How much to use

Most people use half the amount they need. For face and neck, squeeze two full finger lengths of cream onto your index and middle fingers. That's roughly what the SPF on the bottle is tested at. Use less and you get far less protection. Reapply every two hours outdoors, and straight after swimming.