Why we built this
Buying a duvet shouldn't need a degree. Yet search "what tog do I need" and you get a dozen retailer blog posts, a few chart images, and no quick way to actually get your answer. We built TogWise to fix that — a small set of fast, no-nonsense tools that turn the confusing bits of bedding (tog, GSM, sizes, baby sleeping bags) into a clear result you can act on.
Everything runs instantly in your browser. There's nothing to install, no account to make, and no email to hand over.
How we work out the numbers
We don't make figures up. Our conversions and recommendations are built from the values that duvet and sleeping-bag manufacturers publish, plus the standard UK tog and size conventions retailers use.
One thing we're honest about: there is no single magic formula for tog to GSM, because warmth-per-gram depends on the filling. That's exactly why our converter asks you to choose down, feather, microfibre or hollowfibre first — it's the only way to give you a figure that's actually in the right range. Where a number is an estimate, we say so, and we always tell you to check the product's own label before buying.
Our promise
- Free, always. Every tool stays free to use.
- Honest recommendations. What we suggest is based on the room, the season and the filling — never on what pays us most.
- Clear about money. Some "Shop" buttons are affiliate links. As an Amazon Associate we earn from qualifying purchases. If you buy through one, we may get a small commission — it never changes the price you pay.
- We fix mistakes. Spotted something wrong? Tell us and we'll put it right.
A note on the baby tools
Our sleeping-bag guidance is here to help, but it's general information, not medical or safety advice. Always follow your product's label and official safe-sleep guidance, and speak to a health professional if you're unsure about your baby. There's more detail in our terms & disclaimer.
Get in touch
Questions, corrections, or a tool you wish existed? Email tomhm04@gmail.com — we read everything.