Check out this unique Candle Clock that has markings to show how long it can burn. Simple and creative, the candle has been designed by Nathalie Dewez. The Candle Clock measuring 15cm x 6cm is available at Bozar Shop.
If keeping up with the ruler gets tough in your very busy and messy place then you should go for something large and conspicuous. Check out the Ruler Notebook! Printed on its cover are measurements in both cm and inches for your convenience.