Ninety milliliters equals approximately 6 metric tablespoons. A single metric tablespoon is equal to 15 milliliters.
Tablespoon measurements vary by location or style. Volumes in a US or UK tablespoon vary slightly from the metric measurement. Both US and UK tablespoons are slightly smaller — 90 milliliters equals 6.33 UK tablespoons and 6.08 US tablespoons. These volumes generally apply to liquid measurements.
Recipes may call for level or heaped tablespoons when measuring dry ingredients. A level tablespoon is measured by scraping across the top of the spoon to create a level, full spoon. Sixteen level tablespoons of dry or liquid ingredients equals a cup.