I don't have a scale, so I cook using such a tool to measure volume (millilitres): When a recipe tells me to add 40g of granulated sugar, I check websites like this one to perform the conversion.
Cook's Convertor on the App Store
Useful Units Recipe Converter - Mobile App for Android and iOS
Cooking Measurements & Conversion Chart
Sharp Mobile Applications
Cooking Measurements & Conversion Chart
Cooking Units Converter on the App Store
Useful Units Recipe Converter - Mobile App for Android and iOS
Free Kitchen Conversion Chart printable - Sugar Maple Farmhouse
How to use the Kitchen Calculator App