About TablespoonToTeaspoon.com
Reviewed against primary sources May 2026
TablespoonToTeaspoon.com is an independent kitchen-measurement reference published under Digital Signet. The site exists to be a fast, exact, source-anchored answer for the question of how many teaspoons are in a tablespoon, with depth on the parts that home cooks regularly get wrong: the Australian 20 ml tablespoon, the UK dessert spoon, the 1.67x density difference between Diamond Crystal and Morton kosher salt, and the kitchen-spoon-as-medicine-spoon dosing problem the FDA has been warning about since the 1990s.
Why this site exists
The trivial answer (1 tbsp = 3 tsp in US/UK; 1 tbsp = 4 tsp in Australia) gets given correctly by almost every recipe blog. The genuinely useful answer covers the things that change the result: regional standards (US 14.7868 ml from NIST vs UK 15 ml exact from BSI vs AU 20 ml from Standards Australia AS 1291), ingredient density (flour 8 g/tbsp vs water 15 g/tbsp), salt brand variation (Diamond Crystal 9 g/tbsp vs Morton 15 g/tbsp), kitchen-spoon variance (household teaspoons measure 2.5 to 7 ml, not 5 ml), and the decimal-numeral long tail that aggregator-style converters fragment across hundreds of thin pages.
We pull each conversion factor from a named, publicly verifiable primary source and cite the source on the relevant page. Where a figure is a range (such as scoop-method flour at 10 to 12 g/tbsp), we show the range rather than picking a point.
Who builds this
Oliver Wakefield-Smith at Digital Signet. The site sits alongside a handful of sister reference sites covering area, language, and time units; all use the same source-anchored editorial pattern. Cross-links below.
Editorial position
The site is not affiliated with King Arthur Baking, USDA, NIST, BIPM, BSI, Standards Australia, Cook's Illustrated, America's Test Kitchen, Serious Eats, Diamond Crystal, Morton, OXO Good Grips, FDA, AAP, ISMP, or Calpol. Authority names and brand names appear when they are the appropriate reference (Diamond Crystal vs Morton salt density; FDA on kitchen-spoon dosing variance; King Arthur on flour weight per cup), not for paid promotion. There are no paid placements on this site and no live affiliate links today. If affiliate links are added in future, they will be clearly disclosed on the relevant pages.
What this site covers
Editorial principles
Source pattern
Conversion factors anchored to NIST SP 811 (US Customary), BIPM SI Brochure (metric), UK Weights and Measures Act 1985 (UK), and Standards Australia AS 1291 (Australian 20 ml tablespoon). Ingredient density from King Arthur Baking Ingredient Weight Chart, USDA FoodData Central, and Serious Eats / J. Kenji Lopez-Alt salt-density tests. Medicine dosing safety from FDA Office of the Commissioner, AAP, and the Institute for Safe Medication Practices.
No paid placements
Brand names (King Arthur, OXO, Diamond Crystal, Morton, Calpol) appear for editorial specificity, not paid promotion. The site is not affiliated with King Arthur Baking, USDA, NIST, BIPM, Cook's Illustrated, FDA, AAP, Diamond Crystal, Morton, or any cookware brand.
No kitchen-spoon-as-measuring-tool framing
Household teaspoons vary 2.5 ml to 7 ml. We never recommend using kitchen cutlery as a measuring tool for medicine. For recipe precision we recommend a calibrated measuring spoon set; for liquid medicine we recommend the oral syringe or dosing cup supplied with the product.
No fabricated densities or ratios
Every per-ingredient weight figure is cross-checked against King Arthur Baking or USDA FoodData Central. Ranges (flour 8-12 g/tbsp depending on scoop method) are presented as ranges, not point estimates. Where sources disagree we present the spread.
Monthly review cadence
The site is reviewed against primary sources monthly. Every freshness indicator on the site (footer date, hero badge, JSON-LD dateModified) is driven by a single LAST_VERIFIED_DATE constant so dates do not drift apart.
Conservative precision claims
1 US tablespoon = 14.7868 ml is the NIST-derived figure. We round to 14.79 ml in body text but use the full precision in conversion math. Where US (14.79 ml) and UK (15 ml exact) tablespoons differ by 0.21 ml we note the difference rather than papering over it.
Methodology in brief
For the full source list, calculation framework, refresh cadence, and limitations, see the dedicated methodology page. In short: conversion factors come from NIST, BIPM, BSI, Standards Australia (volume standards) and King Arthur Baking, USDA FoodData Central, and Serious Eats (ingredient density). Medicine-dosing safety from FDA / AAP / ISMP / NHS guidance. The full reference list is at /sources.
Disclosures, contact, and corrections
- No paid placements on this site.
- No live affiliate links today. Any future affiliate links will be disclosed inline on the relevant pages.
- This site is not medical advice. For prescription liquid-medicine dosing, follow the supplied dosing device and your pharmacist or product packaging.
- This site is not professional culinary advice. Recipe-specific advice should come from your recipe author.
For corrections, source disagreements, or factual challenges, email us via the contact form at digitalsignet.com. We aim to respond within 5 business days. Please cite the page URL and the specific figure you are challenging, with a counter-source where possible.
Do not email for urgent medical or accidental-overdose questions. For suspected overdose, contact your local poison-control service or emergency services (911 in the US; 999 in the UK; NHS 111 for non-emergency UK medical advice).