Questions about Tantoo
Short answers to the things people ask us most.
Is Tantoo free, and do I need an account?
Tantoo is free to use and there is no account. You do not sign up, you do not confirm an email address, and there is no paid tier holding back the useful parts. Open a tool, get your answer, close the tab. If you want to keep something, such as a room measurement or a conversion you use often, Tantoo saves it on the device you are using rather than in an account somewhere. That means your saved items follow the browser, not you, so they will not appear on your phone if you saved them on a laptop. The site is paid for by advertising.
Where is my data kept?
On your own device. Everything is worked out in the browser, so the numbers you type do not need to be sent anywhere to be converted. Anything you choose to save, such as rooms, appliances, favourite conversions or your shopping list, is stored in your browser's own storage on that device. You can see all of it on the My home screen, export it as a file, or delete it in one go. Clearing your browser data will remove it too, which is worth knowing before you spend an evening measuring a house. If you have a question about privacy, write to privacy@thirdcoffeestudio.com.
How accurate are the conversions?
For fixed relationships, the maths is exact and the only rounding is in how the answer is displayed. An inch is 25.4 millimetres, and a kilogram is a kilogram, so those results are as precise as you need. Other answers are estimates by nature, and we try to say so on the screen. Ingredient weights depend on how the ingredient was packed into the cup. Roast times depend on your oven. Paint coverage depends on the surface and the colour underneath. Running costs depend on the tariff you enter. Use the exact conversions with confidence, and treat the estimates as a sensible starting point rather than a guarantee.
Why does a cup of flour weigh a different amount from a cup of sugar?
Because a cup measures volume, not weight. It tells you how much space an ingredient takes up, and different ingredients fill that space differently. Flour is light and full of air, so a cup of it weighs far less than a cup of granulated sugar, which is dense and packs together. Flour is also the worst offender for inconsistency, since scooping straight from the bag compresses it and can add a noticeable amount to the same cup. That is why a conversion has to know which ingredient you mean. We go through the common ones, and the usual spoon and cup sizes, in our cups to grams guide.
Why do clothing sizes not match between countries?
There is no single international standard that shops must follow. UK, US and EU sizing all grew up separately, from different base measurements and different assumptions about body shape, so the numbers on the label are only loosely related to each other. On top of that, each brand sets its own fit within whatever system it uses, and many quietly adjust sizes over time. The result is that a label number is a rough signal rather than a measurement. This is why our charts work from body measurements wherever possible: a chest in centimetres means the same thing everywhere, while a size 12 does not.
Can I trust the clothing size charts for ordering online?
Use them as a guide, not a guarantee. The charts convert between the standard systems reliably, so they will get you to the right neighbourhood when a site only sells in US or EU sizes. What they cannot do is predict a particular brand's fit. Brands vary by up to a full size in either direction, and cut matters as much as size. So measure yourself, compare against the chart, and then check the retailer's own size guide for that garment if they publish one. Where a brand sits between two sizes, the fabric is a good tiebreaker: little stretch, size up. If returns are awkward or costly, that caution is worth the five minutes.
How do I work out what an appliance costs to run?
You need three things: the appliance's power in watts or kilowatts, how long it runs, and your own price per kilowatt hour. Multiply the power in kilowatts by the hours used to get the energy used, then multiply that by your unit price. As an example only, a 2kW heater running for three hours uses 6kWh, which at an illustrative 25p per kWh would cost about 1.50. The energy tool does this for you, and will also compare two appliances or add up a whole home. There is more on where the awkward numbers come from in our appliance running costs guide.
Where do I find my price per kWh?
On your energy bill or in your supplier's app, usually in the tariff details rather than on the first page. Look for a unit rate given in pence per kWh, and note it separately from the standing charge, which is a daily fee you pay whatever you use. If you have a smart meter display, the unit rate is often shown in its settings. Electricity and gas have different rates, so take the one that matches what the appliance uses. On a time-of-use tariff you will have more than one rate, and the one that applies depends on when the appliance runs. Tantoo does not guess your price, because tariffs change and vary by region.
How much paint do I need for a room?
Start with the wall area: add up the width of each wall, multiply by the height, then subtract the doors and large windows. Divide that area by the coverage printed on the tin, which is usually given in square metres per litre, and multiply by the number of coats. Two coats is normal, and three is wise over a strong colour or bare plaster. Ceilings and woodwork are counted separately, as they often need a different paint. The projects tool does the arithmetic and turns it into tins you can actually buy. Our paint quantity guide covers coverage figures, primer and the usual mistakes.
Does Tantoo work offline?
Yes, after the first visit. Once your browser has loaded the site, the tools are kept locally and will open again without a connection. That is useful in the middle of a DIY shop with no signal, or on a kitchen worktop where the wifi is poor. Because the calculations happen in the browser anyway, an offline conversion is the same conversion. Your saved rooms, appliances and shopping list are on the device, so they are available offline too. A few things do need a connection, such as loading the site for the very first time or picking up an update, and your browser may clear the stored copy if you clear site data.
Can I put a Tantoo converter on my own website?
Yes. Tantoo offers embeddable widgets, so you can drop a single converter or calculator into your own page rather than sending readers away to find one. It suits a recipe blog that needs cups and grams in the margin, or a trade site that wants a materials calculator next to its advice. The widget behaves like the full tool, including working out the answer in the visitor's browser. There is no charge for using one. If you would like to embed something, or you need a tool configured a particular way for your page, write to tantoo@thirdcoffeestudio.com and tell us what you are building.
Who makes Tantoo?
Tantoo is built by Third Coffee Studio Ltd, a small independent company registered in England and Wales, company number 17517422. It is a short list of people rather than a large team, which is why the site is plain and the tools are the point. We also run Codeshed at codeshed.app, which makes free QR codes and barcodes. Tantoo is paid for by advertising rather than subscriptions, so the tools stay free and there is nothing to sign up for. If something is wrong, unclear or missing, we would rather hear about it: tantoo@thirdcoffeestudio.com. For privacy questions, use privacy@thirdcoffeestudio.com.
Something else?
Email tantoo@thirdcoffeestudio.com and a person will read it. The guides go into more detail.
Tantoo is a trading name of Third Coffee Studio Ltd, registered in England and Wales, company number 17517422.