SPF Reapplication Timer
Plan your sunscreen through the day — when to reapply from your first application to the end of sun exposure, and roughly how much product it takes.
Your reapplication schedule
- 9:00 AM — apply generously
- 11:00 AM — reapply
- 1:00 PM — reapply
- 3:00 PM — reapply
- 5:00 PM — reapply
No sunscreen lasts all day. Reapply after towelling off, heavy sweating, or swimming, and remember shade and clothing do part of the work.
The best sunscreen is the one you reapply
Sun protection is the single most effective step in any skincare routine, natural or otherwise — but a morning application alone won’t carry you through the day. Filters degrade in light, and product rubs, sweats, and washes away, so the number on the bottle only holds if you top it up. The standard advice is simple: reapply every couple of hours, and more often in and out of water.
This timer lays those top-ups out on the clock and adds up the product, using the well-known shot-glass guideline for the body, so you can pack enough and actually keep the habit.
Frequently Asked Questions
How often should I reapply sunscreen?
As a general rule, every two hours of sun exposure, and sooner — roughly every 40 to 80 minutes depending on the product's water-resistance rating — when you're swimming or sweating heavily. Reapply after towelling off, too. The first, generous application in the morning is only the start; protection fades through the day as filters break down and product rubs away.
How much sunscreen should each application be?
Most people under-apply, which lowers the protection well below the SPF on the bottle. The common guideline is about a shot glass (roughly 30 ml) to cover the whole body and about a quarter-teaspoon for the face and neck. The tool multiplies your per-application amount by the number of applications so you can see how much a day out really needs.
Does mineral sunscreen need reapplying as often as chemical?
Yes. Whether the filters are mineral (zinc oxide, titanium dioxide) or chemical, sunscreen still rubs, sweats, and washes off, so the every-two-hours habit applies to both. Water resistance buys time in water but isn't waterproof, and no formula lasts a full day on one application.
Is this timer medical advice?
No. It's a practical scheduler built on widely published reapplication intervals, not medical or dermatological advice. Sun sensitivity, medications, altitude, and reflective surfaces all change your real needs, and shade and clothing matter as much as any product. For sun-protection guidance tied to your skin or a condition, ask a professional.
Educational scheduler only, not medical or dermatological advice. Real needs vary with skin, medication, altitude, and reflection off water, sand, and snow. Seek shade, cover up, and follow the product’s own directions.