Solution Prep Calculator
A free online solution preparation calculator for laboratory use. Calculate mass of solute for desired molar solutions, perform stock dilutions with C1V1=C2V2, convert between percent and molarity, and plan serial dilutions. Includes presets for common reagents (NaCl, Tris, HEPES, EDTA) and buffer recipes (PBS, TBS, TAE) — all computed in your browser.
Mass Required
ご提案はありますか？
新しいツールのリクエストや改善提案をお待ちしています — Slackコミュニティにご参加ください！
What is a Solution Prep Calculator?
A solution preparation calculator helps laboratory scientists determine the exact amounts of solute and solvent needed to prepare solutions of specific concentrations. It handles common calculations including mass-from-molarity (how many grams to weigh for a molar solution), stock dilutions using the C1V1 = C2V2 equation, percent-to-molarity conversions, and serial dilution planning. These calculations are routine in any wet lab setting from molecular biology to analytical chemistry.
How to Use This Calculator
- Select a calculation mode: Mass from Molarity, Dilution, % to Molarity, or Serial Dilution
- Enter known values (concentration, volume, molecular weight) or select a reagent preset
- Click Calculate to get the result instantly
- Use buffer recipe references to prepare common buffers like PBS, TBS, or TAE
- For serial dilutions, specify the dilution factor, number of tubes, and volume per tube
Frequently Asked Questions
How do I calculate grams needed for a molar solution?
Use the formula: mass (g) = molarity (M) × volume (L) × molecular weight (g/mol). For example, to make 500 mL of 1 M NaCl (MW = 58.44): mass = 1 × 0.5 × 58.44 = 29.22 g. Dissolve 29.22 g NaCl in water, then bring the total volume to 500 mL.
What is the C1V1 = C2V2 dilution formula?
C1V1 = C2V2 relates stock concentration (C1), stock volume to use (V1), desired final concentration (C2), and desired final volume (V2). To find V1: V1 = C2 × V2 / C1. For example, to make 100 mL of 0.1 M HCl from 1 M stock: V1 = 0.1 × 100 / 1 = 10 mL. Take 10 mL stock and add 90 mL water.
How do I convert percent (% w/v) to molarity?
Molarity = (% w/v × 10) / molecular weight. The factor of 10 converts from g/100mL to g/L. For example, 10% NaCl (MW 58.44): M = (10 × 10) / 58.44 = 1.71 M. This formula assumes % w/v means grams of solute per 100 mL of solution.