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Percent Solution Calculator

Chemistry

Calculate weight by volume (w/v), weight by weight (w/w), and volume by volume (v/v) percent solutions, and grams needed for any solution volume.

Reviewed by the thecalcu.com team · Last updated July 11, 2026

5 g
g
100 mL
mL

Percent Solution (% w/v)

5
Concentration (g/L)
50
Grams per 100 mL
5

This calculator computes your Percent Solution (% w/v), Concentration (g/L), Grams per 100 mL from the values you enter.

Inputs
Mass of SoluteVolume of Solution
Outputs
Percent Solution (% w/v)Concentration (g/L)Grams per 100 mL

What is a Percent Solution?

The Percent Solution Calculator computes the weight-by-volume concentration (% w/v) of a solution from the mass of solute (in grams) and the final volume of solution (in mL). It returns the % w/v concentration, the equivalent concentration in g/L, and grams per 100 mL, the three most common ways to express percent solution concentration in a single calculation.

Percent solution is the most intuitive concentration expression in everyday chemistry, pharmacy, and food science. A 5% w/v solution contains 5 grams of solute in every 100 mL of solution, a definition that is easy to prepare without knowing the molar mass, which makes it widely used for substances with uncertain or variable molecular weights (biological extracts, food additives, industrial chemicals).

The % w/v definition is the standard in the Indian Pharmacopoeia (IP) for injectable solutions, eye drops, and syrups. Normal saline (0.9% NaCl), 5% dextrose IV, and 70% IPA disinfectant are all specified as percent concentrations rather than molarity. Converting between percent solutions and molarity requires the molar mass, use the Concentration Calculator for this. The Percent Solution Calculator handles the preparatory question: given a mass and volume, what is the percent concentration?

The related % w/w (weight by weight) concentration is used when solutions are weighed rather than volumetrically measured, this is important for concentrated solutions (like 98% H₂SO₄) where the density is very different from 1 g/mL, making % w/v and % w/w significantly different. For dilute aqueous solutions (< ~5%), water's density is close to 1 g/mL, so % w/v and % w/w are nearly equal and the distinction is rarely important.

In India's school curriculum, percent solutions appear in NCERT Class 12 Chapter 2 and are a standard practical skill in food testing (FSSAI food standards specify % w/v for preservatives and additives) and water treatment (NaOCl concentration in % for disinfection). For the dilution step, converting a concentrated percent solution to a working concentration, use the Solution Dilution Calculator.

Why Use a Percent Solution Calculator?

Preparing a percent solution requires a simple division: mass ÷ volume × 100. But two common errors arise: using the mass of water added rather than the final solution volume (which should include the solute's own volume), and confusing % w/v with % w/w when density ≠ 1 g/mL.

Key use cases:

  • Lab prep verification: Confirm that a prepared solution (weighed mass, measured to final volume) meets the target % w/v specification.
  • Pharmacological preparation: Check that a compounded drug solution meets the IP or NLEM specification in % w/v.
  • Food quality: Calculate the % w/v of preservative (salt, sugar, vinegar) in a food sample to compare with FSSAI permitted limits.
  • Antiseptic preparation: Verify the percent concentration of bleach or ethanol diluted for surface disinfection.

The Molarity Calculator is used when molarity rather than percent is the target; the Percent Solution Calculator and Molarity Calculator together cover the most common solution concentration calculations.

Who Should Use This Calculator?

NEET aspirants and Class 12 biology students who encounter percent solutions in physiology contexts, blood glucose (80–120 mg/dL ≈ 0.08–0.12% w/v glucose), saline infusions (0.9% w/v NaCl), and kidney filtrate osmolarity.

Pharmacy students and hospital pharmacists in India who prepare and verify IV solutions, oral syrups, and topical preparations. The IP expresses almost all concentrations in % w/v, this calculator confirms the batch.

Food science and food quality students testing the salt content of pickles, the sugar content of jams, or the acidity of vinegar for compliance with FSSAI standards. Use alongside the ppm to Molarity Calculator for trace-level analysis.

School and undergraduate chemistry lab students preparing buffer solutions, staining solutions, and gel systems (e.g., 1.5% agarose gel = 1.5 g agarose in 100 mL TAE buffer). The Percent Solution Calculator confirms the recipe.

Environmental and water testing professionals preparing chemical reagent solutions for standard methods, many reagent concentrations in IS 3025, IS 10500, and BIS water testing methods are specified as % w/v.

What Insights Does the Percent Solution Calculator Give You?

Percent Solution (% w/v) is the primary highlighted output, grams of solute per 100 mL of solution, expressed as a percentage. A result of 5% means the solution contains 5 g of solute per 100 mL. Compare this against the target specification (IP, FSSAI, protocol) to verify the preparation.

Concentration (g/L) shows the same concentration in grams per litre. Since g/L = % w/v × 10, a 5% solution = 50 g/L. This form is useful for reporting to regulatory standards expressed in g/L or mg/L (multiply by 1000), and for stoichiometric calculations that need a mass per volume value.

Grams per 100 mL is numerically equal to % w/v, it makes the definition explicit. For clarity in lab reports and drug labels, "5 g per 100 mL" is sometimes preferred over "5%" because it avoids ambiguity about whether % w/v or % w/w is meant.

How to use this Percent Solution calculator

  1. Weigh your solute, measure the mass of solute to dissolve. For 5% NaCl (to make 100 mL), you will need 5 g.
  2. Enter Mass of Solute, type the mass in grams into the Mass of Solute field. For 5 g, enter 5.
  3. Enter Volume of Solution, type the final volume of the solution (after dissolving and making up to volume) into the Volume of Solution field in mL. For a 100 mL flask, enter 100.
  4. Read Percent Solution (% w/v), the highlighted result shows the concentration. If you dissolved 5 g in 100 mL, you get 5% w/v.
  5. Read Concentration (g/L), note the g/L value for reporting or for comparison against standards. 5% = 50 g/L = 50,000 mg/L.
  6. Check grams per 100 mL, this equals % w/v numerically. For dilution to a lower percent, use the Solution Dilution Calculator with concentrations in % as C₁ and C₂.
Show formula & methodology ↓Show less ↑

Formula & Methodology

Percent solution (% w/v) formula:

> % w/v = (mass of solute in g ÷ volume of solution in mL) × 100

Equivalent forms:

> g/L = (mass of solute in g ÷ volume of solution in mL) × 1000 = % w/v × 10

> g per 100 mL = % w/v (numerically identical)

To convert % w/v to molarity:

> Molarity (M) = (% w/v × 10) ÷ molar mass (g/mol)

Worked example 1, Normal saline preparation:

Prepare 500 mL of 0.9% w/v NaCl:
- Mass of NaCl = 0.9 ÷ 100 × 500 = 4.5 g
- Dissolve 4.5 g NaCl in water and make up to 500 mL
- Molarity: 0.9% × 10 ÷ 58.44 = 0.154 M NaCl (isotonic)

Worked example 2, Glucose IV concentration verification:

A 5% dextrose (glucose, MW = 180.16 g/mol) IV bag contains 25 g in 500 mL:
- % w/v = (25 ÷ 500) × 100 = 5% ✓
- g/L = 50 g/L
- Molarity = 50 ÷ 180.16 = 0.278 M glucose

Worked example 3, Bleach disinfection solution (FSSAI/hospital context):

Commercial bleach = 4% w/v NaOCl. To prepare 1 litre of 0.5% NaOCl for surface disinfection:
- C₁V₁ = C₂V₂: V₁ = (0.5 × 1000) ÷ 4 = 125 mL bleach + 875 mL water
- Verify: (125 × 4%) ÷ 1000 = 0.5% NaOCl ✓
- Use the Solution Dilution Calculator to compute this directly

Frequently Asked Questions

What is a percent solution?
A percent solution expresses concentration as the amount of solute per 100 units of solution. Weight by volume (% w/v) is the most common: grams of solute per 100 mL of solution. Weight by weight (% w/w) is grams of solute per 100 g of solution. Volume by volume (% v/v) is mL of solute per 100 mL of solution. The Percent Solution Calculator computes % w/v (the lab standard for dissolved solids) from mass and volume inputs.
What is % w/v and how is it calculated?
% w/v (weight per volume percent) = (mass of solute in grams ÷ volume of solution in mL) × 100. For example, 5 g of NaCl dissolved in 100 mL of solution = 5% w/v NaCl. One 'percent' w/v means 1 g of solute per 100 mL of solution = 10 g/L. This is the standard expression for drug concentrations in Indian Pharmacopoeia (IP) for injections, syrups, and eye drops.
What is the difference between % w/v, % w/w, and % v/v?
% w/v (g solute per 100 mL solution) is used for solid solutes dissolved in liquid solvents, the most common lab expression. % w/w (g solute per 100 g solution) is used when the solution is weighed rather than volumetrically measured, and is required for very precise work or concentrated solutions where density deviates significantly from 1 g/mL. % v/v (mL solute per 100 mL solution) is used for liquid solutes in liquid solvents, such as alcohol in water. For dilute aqueous solutions, % w/v ≈ % w/w because water density ≈ 1 g/mL.
How do I convert % w/v to molarity?
Molarity (M) = (% w/v × 10) ÷ molar mass. The factor 10 converts from g per 100 mL to g per litre. For example, 5% w/v NaCl: M = (5 × 10) ÷ 58.44 = 50 ÷ 58.44 = 0.856 M. Alternatively, g/L = % w/v × 10, then M = g/L ÷ molar mass. Use the Concentration Calculator for the mass-molar mass-volume route to molarity.
What percentage solutions are used in Indian hospitals and pharmacies?
Common solutions in Indian hospital practice: Normal Saline = 0.9% NaCl (w/v), 5% Dextrose (D5W) = 5% glucose (w/v), 25% Dextrose (for hypoglycaemia) = 25% glucose (w/v), 3% H₂O₂ (hydrogen peroxide, antiseptic) = 3% w/v, 70% Isopropyl Alcohol (IPA) = 70% v/v. These are standardised per National List of Essential Medicines (NLEM) and are prepared using w/v or v/v definitions depending on whether the solute is solid or liquid.
What is the percent solution of common antiseptics and disinfectants?
Commonly encountered in Indian healthcare and lab settings: Betadine (povidone-iodine) = 10% w/v; Dettol (chloroxylenol) solution = 4.8% w/v; Savlon (chlorhexidine + cetrimide) = 0.5% + 0.5% w/v; 70% ethanol or IPA for surface disinfection = 70% v/v; bleach solutions for instrument disinfection = 0.5% or 1% sodium hypochlorite (from household bleach which is 3–5% NaOCl, diluted using C₁V₁ = C₂V₂).
How do I prepare a 10% NaCl solution?
Dissolve 10 g of NaCl (table salt) in enough water to make 100 mL of solution (not in 100 mL of water, the final volume must be 100 mL). This gives 10% w/v NaCl. For 500 mL: dissolve 50 g NaCl and make up to 500 mL. Molarity: 10% NaCl = (10 × 10) ÷ 58.44 = 1.71 M. In Indian science fairs and school labs, saturated NaCl is about 26% w/v (density ~1.2 g/mL).
How do I use the Percent Solution Calculator?
Enter the mass of solute in grams in the Mass of Solute field, and the final volume of solution in mL in the Volume of Solution field. The calculator outputs the % w/v concentration, g/L (same as % w/v × 10), and grams per 100 mL (which equals % w/v numerically). The steps panel shows the division clearly.
What percentage solution is used for glucose in IV infusions in India?
The most common glucose (dextrose) IV infusions used in India are 5% (50 g/L), 10% (100 g/L), and 25% (250 g/L). The 5% solution is approximately isotonic (274 mOsm/L) and is used for hydration. The 25% solution is hypertonic and is used in emergency treatment of hypoglycaemia. Doses are prescribed in mg/kg/hour or mL/hour, requiring back-conversion from percent to grams per mL: 5% = 0.05 g/mL = 50 mg/mL.
How is percent solution taught in India's chemistry curriculum?
Percent by mass (w/w) and percent by volume (v/v) are introduced in NCERT Class 12 Chemistry Chapter 2 (Solutions) alongside molarity and molality. Percent by weight/volume (% w/v) is taught in pharmacy and biology courses. JEE and NEET problems on solutions may require converting between % w/w, molarity, and molality, the Percent Solution Calculator handles the % w/v to g/L step.
What is the relationship between percent solution and g/L?
g/L = % w/v × 10. This is because % w/v is grams per 100 mL, and there are 10 × 100 mL in 1 litre: g/L = (g/100 mL) × (1000 mL/L) = (% w/v/100) × 1000 = % w/v × 10. For example, 5% w/v = 50 g/L; 0.9% w/v NaCl = 9 g/L. Knowing this conversion is essential for clinical drug preparation and environmental standards expressed in mg/L.
Can the Percent Solution Calculator be used for solutions containing multiple solutes?
The calculator computes % w/v for a single solute. For multi-component solutions (e.g., PBS containing NaCl, KCl, Na₂HPO₄, and KH₂PO₄), calculate the % w/v for each component individually by entering the mass of that component and the total solution volume. The total % w/v of the solution (if needed) is the sum of all individual % w/v values. For molarity of each component, use the Concentration Calculator with the individual masses.
Also known as
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