Percentage / Ratio Strength Converter
Convert between % strength, ratio strength (1:N), and mg/mL — all three directions supported.
All three formats
- Percentage1%
- Ratio strength1:100
- mg per mL10 mg/mL
- Equivalent in g/L10 g/L
Frequently asked questions
It means 1 gram of solute per 1,000 mL of solution. That equals 0.1% w/v, or 1 mg/mL. The 'ratio strength' notation is most common for very dilute solutions (adrenaline 1:1000, 1:10,000) because writing 0.01% or 0.1 mg/mL feels less concrete for clinical use.
Historical convention. The ratio format makes it easy to scale: if 1 mL of 1:1000 adrenaline contains 1 mg, then 10 mL of 1:10,000 also contains 1 mg. In cardiac arrest, this lets you draw up the same dose from different vial concentrations without recalculating. Many modern hospitals now also label vials with mg content to reduce errors.
Only for dilute aqueous solutions where 1 mL ≈ 1 g. For ointments, creams, and viscous liquids, w/v and w/w differ. Always check the label. Pharmacy convention defaults to w/v for liquids and w/w for semisolids.
% w/v = grams of solute per 100 mL of solution (e.g. 0.9% sodium chloride = 0.9 g per 100 mL water). % v/v = mL of solute per 100 mL of solution (e.g. 70% alcohol = 70 mL pure alcohol per 100 mL solution). For solid solutes, w/v is always used.
Adrenaline (epinephrine) 1:1000 = 0.1% = 1 mg/mL · 1:10,000 = 0.01% = 0.1 mg/mL. Lidocaine 2% = 1:50 = 20 mg/mL. Atropine 0.05% = 1:2000 = 0.5 mg/mL. Hydrocortisone 1% = 1:100 = 10 mg/mL. Bupivacaine 0.5% = 1:200 = 5 mg/mL.
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