Teaspoons to Milliliters Converter (tsp to mL)
Convert teaspoons (tsp) to milliliters (mL) instantly with real-time two-way calculation, exact formulas, and comprehensive reference tables.
Conversion Formula & Exact Calculation
How to convert Teaspoons to Milliliters: Multiply by 4.92892.
US Teaspoons vs. Metric & Medical Spoons
In cooking and pharmacology, spoon volumes can vary slightly depending on whether US customary or metric standards are used:
- US Customary Teaspoon: Exactly 4.92892 mL (used for American recipe books).
- Metric Teaspoon / Medicine Dosing: Rounded to exactly 5.0 mL by the FDA and pharmaceutical industry for safe liquid medication dosing.
- 3 Teaspoons = 1 Tablespoon: 1 tbsp = 14.79 mL (or 15 mL metric).
Teaspoons to Milliliters Quick Reference Table
| Teaspoons (tsp) | Milliliters (mL) |
|---|---|
| 1/8 (0.125) tsp | 0.616115 mL |
| 1/4 (0.25) tsp | 1.23223 mL |
| 1/3 (0.333) tsp | 1.642973 mL |
| 1/2 (0.5) tsp | 2.46446 mL |
| 2/3 (0.667) tsp | 3.285947 mL |
| 3/4 (0.75) tsp | 3.69669 mL |
| 1 tsp | 4.92892 mL |
| 1 1/2 (1.5) tsp | 7.39338 mL |
| 2 tsp | 9.85784 mL |
| 2 1/2 (2.5) tsp | 12.3223 mL |
| 3 tsp | 14.78676 mL |
| 4 tsp | 19.71568 mL |
| 5 tsp | 24.6446 mL |
| 10 tsp | 49.2892 mL |
| 25 tsp | 123.223 mL |
| 50 tsp | 246.446 mL |
| 100 tsp | 492.892 mL |
| 250 tsp | 1,232.23 mL |
| 500 tsp | 2,464.46 mL |
| 1,000 tsp | 4,928.92 mL |
⚠️ 5 Fatal Metrology & Dimensional Analysis Traps
Unit conversion errors have historically caused catastrophic aerospace accidents, structural overloads, and pharmacological dosage failures. Watch out for these 5 traps:
Linear conversions do not scale linearly into area or volume. While 1 meter = 100 centimeters, 1 square meter = 10,000 cm² (100²), and 1 cubic meter = 1,000,000 cm³ (100³). Applying linear conversion ratios to surface area, HVAC ductwork, or tank volume causes severe 100× to 1,000× estimation errors.
US fluid ounces (29.57 mL) and British Imperial fluid ounces (28.41 mL) are different. Even more drastically, a US liquid gallon is 128 US fl oz (3.785 L), while a UK Imperial gallon is 160 UK fl oz (4.546 L)—a massive 20.1% volume discrepancy that causes critical miscalculations in aviation fueling and chemical synthesis.
Standard formulas (°F = °C × 1.8 + 32) apply strictly to absolute scale readings. When converting temperature differentials or temperature changes (ΔT), the +32 offset MUST be omitted: a temperature change of 1°C equals a change of exactly 1.8°F. Adding 32 to heat pump delta-T metrics, building insulation R-values, or thermal expansion calculations corrupts engineering calculations.
Hardware manufacturers sell storage in decimal SI prefixes (1 GB = 1,000,000,000 bytes = 10⁹), whereas operating systems like Windows calculate filesystem allocation in binary IEC prefixes (1 GiB = 1,073,741,824 bytes = 2³⁰). This causes a 1 TB drive to register as approximately 931 GB in OS file explorers, leading to unexpected disk partition shortfalls.
Truncating decimal places during intermediate conversion steps compounds floating-point error across multi-stage formulas. In aerospace telemetry, CNC metal fabrication, or pharmaceutical microgram compounding, conversions must retain full IEEE 754 64-bit double precision until final display formatting.