RNA-LNP Formulation Calculator

Optimize your lipid nanoparticle formulation with the RNA-LNP Formulation Calculator. Quickly calculate the required amounts of lipids and nucleic acids (mRNA, siRNA, ASO…) for your lipid nanoparticle formulations. Select your lipid composition, RNA payload, and formulation parameters—the calculator does the rest!
free to use free to use

Calculator methods:

Choose “Lipid concentration” if working with a known total concentration in your initial lipid mix or choose “RNA concentration” if working with a target RNA concentration in your final LNP formulation.

Developped by
Inside Therapeutics
for the Scientific community

A. Indicate the total volume and the concentration of your initial lipid mix

Total concentration of lipids in your initial lipid mix * info Lipid concentration in the organic phase before mixing. Determines RNA encapsulation and LNP stability.
Total volume of initial lipid mix you aim at preparing * info Total organic phase volume. Essential for correct lipid quantities and formulation consistency. (mL)

B. Choose your 4 lipids and their molar ratio

Lipid 1:

Lipids * info Core LNP components: structural, sterol, ionizable, and PEGylated lipids. Each impacts RNA delivery.
Lipid 1 * info Core LNP components: structural, sterol, ionizable, and PEGylated lipids. Each impacts RNA delivery.
Type info Defines lipid function: structural (stability), sterol (fluidity), ionizable (RNA binding), PEG (circulation).
Structural
N info Protonatable amine groups per lipid. Critical for RNA binding and endosomal escape.
(number)
-
Molar weight info Lipid molecular weight (g/mol). Used to calculate molar concentrations in the final formulation.
(g/mol)
-
Molar ratio * info Relative lipid proportion. Affects LNP structure, RNA encapsulation, and biological performance. Warning: Sum of molar ratios must equal 100%.
(%)

Warning: Sum of molar ratios must equal 100%.

Mass to collect info Lipid mass needed for formulation, based on total lipid concentration and molar ratios.
(mg)
-

Lipid 2:

Lipid 2 * info Core LNP components: structural, sterol, ionizable, and PEGylated lipids. Each impacts RNA delivery.
Type info Defines lipid function: structural (stability), sterol (fluidity), ionizable (RNA binding), PEG (circulation).
Sterol
N info Protonatable amine groups per lipid. Critical for RNA binding and endosomal escape.
(number)
0
Molar weight info Lipid molecular weight (g/mol). Used to calculate molar concentrations in the final formulation.
(g/mol)
-
Molar ratio * info Relative lipid proportion. Affects LNP structure, RNA encapsulation, and biological performance. Warning: Sum of molar ratios must equal 100%.
(%)

Warning: Sum of molar ratios must equal 100%.

Mass to collect info Lipid mass needed for formulation, based on total lipid concentration and molar ratios.
(mg)
-

Lipid 3:

Lipid 3 * info Core LNP components: structural, sterol, ionizable, and PEGylated lipids. Each impacts RNA delivery.
Type info Defines lipid function: structural (stability), sterol (fluidity), ionizable (RNA binding), PEG (circulation).
Cationic/Ionizable
N info Protonatable amine groups per lipid. Critical for RNA binding and endosomal escape.
(number)
-
Molar weight info Lipid molecular weight (g/mol). Used to calculate molar concentrations in the final formulation.
(g/mol)
-
Molar ratio * info Relative lipid proportion. Affects LNP structure, RNA encapsulation, and biological performance. Warning: Sum of molar ratios must equal 100%.
(%)

Warning: Sum of molar ratios must equal 100%.

Mass to collect info Lipid mass needed for formulation, based on total lipid concentration and molar ratios.
(mg)
-

Lipid 4:

Lipid 4 * info Core LNP components: structural, sterol, ionizable, and PEGylated lipids. Each impacts RNA delivery.
Type info Defines lipid function: structural (stability), sterol (fluidity), ionizable (RNA binding), PEG (circulation).
PEG-Lipid
N info Protonatable amine groups per lipid. Critical for RNA binding and endosomal escape.
(number)
0
Molar weight info Lipid molecular weight (g/mol). Used to calculate molar concentrations in the final formulation.
(g/mol)
-
Molar ratio * info Relative lipid proportion. Affects LNP structure, RNA encapsulation, and biological performance. Warning: Sum of molar ratios must equal 100%.
(%)

Warning: Sum of molar ratios must equal 100%.

Mass to collect info Lipid mass needed for formulation, based on total lipid concentration and molar ratios.
(mg)
-

Lipid 1:

Stock solution info Lipid concentration in solvent (e.g., ethanol).
(mg/mL)
Volume to sample info Lipid stock volume needed to obtain the correct lipid amount for LNP preparation.
(µL)
-

Lipid 2:

Stock solution info Lipid concentration in solvent (e.g., ethanol). Defines volumes required for formulation.
(mg/mL)
Volume to sample info Lipid stock volume needed to obtain the correct lipid amount for LNP preparation.
(µL)
-

Lipid 3:

Stock solution info Lipid concentration in solvent (e.g., ethanol). Defines volumes required for formulation.
(mg/mL)
Volume to sample info Lipid stock volume needed to obtain the correct lipid amount for LNP preparation.
(µL)
-

Lipid 4:

Stock solution info Lipid concentration in solvent (e.g., ethanol). Defines volumes required for formulation.
(mg/mL)
Volume to sample info Lipid stock volume needed to obtain the correct lipid amount for LNP preparation.
(µL)
-
Solvent to supplement info Extra solvent volume required to reach the target lipid concentration.
(µL)

Warning: Stock solutions too dilluted to reach target lipid concentration.

-

C. Choose your RNA and the length

RNA name info Indicate the name or type of RNA.
RNA name info Indicate the name or type of RNA.
RNA length * info Number of nucleotides (nucleoside monophosphate).
Molecular weight/base set to 330g/mol/base (F. H. Stephenson, Calculations for Molecular Biology and Biotechnology, 2003, 5 - Quantitation of Nucleic Acids, Academic Press, 90-108. ).
RNA length * info Number of nucleotides (nucleoside monophosphate).
Molecular weight/base set to 330g/mol/base (F. H. Stephenson, Calculations for Molecular Biology and Biotechnology, 2003, 5 - Quantitation of Nucleic Acids, Academic Press, 90-108. ).
N/P ratio * info Molar ratio of Azote atoms from the lipids (N) over the Phosphorus of the RNA (P) (L. Schoenmaker, et al. Int. J. Pharm., 2021, 601, 120586.).
N/P ratio * info Molar ratio of Azote atoms from the lipids (N) over the Phosphorus of the RNA (P).
FRR (aq : lip) * info FRR: Flow Rate Ratio is the ratio between the flow rates of the aqueous phase (containing your RNA) and the organic phase (containing your lipids). This value is typically around 3 for RNA-LNPs.
FRR (aq : lip) * info FRR: Flow Rate Ratio is the ratio between the flow rates of the aqueous phase (containing your RNA) and the organic phase (containing your lipids). This value is typically around 3 for RNA-LNPs.
Final volume sample * info Total LNP formulation volume after lipid and aqueous phase mixing.
(mL)
Final volume sample * info Total LNP formulation volume after lipid and aqueous phase mixing.
(mL)

D. Calculator Results

Volume of buffer RNA solution required info RNA phase volume needed to achieve the desired formulation.
(mL)
-
Volume of lipid mix required info Lipid phase volume needed to achieve the desired formulation.
(mL)
-
Initial RNA concentration in aqueous buffer info Concentration of the RNA phase before mixing. Determines final RNA content in LNPs.
-
RNA concentration in the sample after formulation info Final RNA concentration post-formulation. Validates consistency.
(µM)
-
RNA weight per sample info Total RNA mass in the final LNP formulation, based on concentration and volume.
(mg)
-

E. Save results in pdf and xls

Send your calculations straight to your inbox in XLS and PDF files.

You'll also get a link to reopen the calculator with your data pre-filled —no need to start over!

    A. Choose your RNA parameters & your Targeted final RNA Concentration

    RNA name info Indicate the name or type of RNA.
    RNA name info Indicate the name or type of RNA.
    RNA length * info Number of nucleotides (nucleoside monophosphate).
    Molecular weight/base set to 330g/mol/base (F. H. Stephenson, Calculations for Molecular Biology and Biotechnology, 2003, 5 - Quantitation of Nucleic Acids, Academic Press, 90-108. ).
    RNA length * info Number of nucleotides (nucleoside monophosphate).
    Molecular weight/base set to 330g/mol/base (F. H. Stephenson, Calculations for Molecular Biology and Biotechnology, 2003, 5 - Quantitation of Nucleic Acids, Academic Press, 90-108. ).
    N/P ratio * info Molar ratio of Azote atoms from the lipids (N) over the Phosphorus of the RNA (P) (L. Schoenmaker, et al. Int. J. Pharm., 2021, 601, 120586.).
    N/P ratio * info Molar ratio of Azote atoms from the lipids (N) over the Phosphorus of the RNA (P) (L. Schoenmaker, et al. Int. J. Pharm., 2021, 601, 120586.).
    FRR (aq : lip) * info FRR: Flow Rate Ratio is the ratio between the flow rates of the aqueous phase (containing your RNA) and the organic phase (containing your lipids). This value is typically around 3 for RNA-LNPs.
    FRR (aq : lip) * info FRR: Flow Rate Ratio is the ratio between the flow rates of the aqueous phase (containing your RNA) and the organic phase (containing your lipids). This value is typically around 3 for RNA-LNPs.
    Final volume sample * info Total LNP formulation volume after lipid and aqueous phase mixing.
    (mL)
    Final volume sample * info Total LNP formulation volume after lipid and aqueous phase mixing.
    (mL)
    RNA concentration in the sample after formulation * info Final RNA concentration post-formulation. Validates consistency.

    B. Indicate the total volume of your lipid mix

    Volume of lipid mix required info Lipid phase volume needed to achieve the desired formulation.
    (mL)
    -
    Total volume of initial lipid mix you aim at preparing * info Total organic phase volume. Essential for correct lipid quantities and formulation consistency.
    (mL)

    Reminder: It must be more than the volume of lipid required.

    C. Choose your 4 lipids and their molar ratio

    Lipid 1:

    Lipids * info Core LNP components: structural, sterol, ionizable, and PEGylated lipids. Each impacts RNA delivery.
    Lipid 1 * info Core LNP components: structural, sterol, ionizable, and PEGylated lipids. Each impacts RNA delivery.
    Type info Defines lipid function: structural (stability), sterol (fluidity), ionizable (RNA binding), PEG (circulation).
    Structural
    N info Protonatable amine groups per lipid. Critical for RNA binding and endosomal escape.
    (number)
    -
    Molar weight info Lipid molecular weight (g/mol). Used to calculate molar concentrations in the final formulation.
    (g/mol)
    -
    Molar ratio * info Relative lipid proportion. Affects LNP structure, RNA encapsulation, and biological performance. Warning: Sum of molar ratios must equal 100%.
    (%)

    Warning: Sum of molar ratios must equal 100%.

    Mass to collect info Lipid mass needed for formulation, based on total lipid concentration and molar ratios.
    (mg)
    -

    Lipid 2:

    Lipid 2 * info Core LNP components: structural, sterol, ionizable, and PEGylated lipids. Each impacts RNA delivery.
    Type info Defines lipid function: structural (stability), sterol (fluidity), ionizable (RNA binding), PEG (circulation).
    Sterol
    N info Protonatable amine groups per lipid. Critical for RNA binding and endosomal escape.
    (number)
    0
    Molar weight info Lipid molecular weight (g/mol). Used to calculate molar concentrations in the final formulation.
    (g/mol)
    -
    Molar ratio * info Relative lipid proportion. Affects LNP structure, RNA encapsulation, and biological performance. Warning: Sum of molar ratios must equal 100%.
    (%)

    Warning: Sum of molar ratios must equal 100%.

    Mass to collect info Lipid mass needed for formulation, based on total lipid concentration and molar ratios.
    (mg)
    -

    Lipid 3:

    Lipid 3 * info Core LNP components: structural, sterol, ionizable, and PEGylated lipids. Each impacts RNA delivery.
    Type info Defines lipid function: structural (stability), sterol (fluidity), ionizable (RNA binding), PEG (circulation).
    Cationic/Ionizable
    N info Protonatable amine groups per lipid. Critical for RNA binding and endosomal escape.
    (number)
    -
    Molar weight info Lipid molecular weight (g/mol). Used to calculate molar concentrations in the final formulation.
    (g/mol)
    -
    Molar ratio * info Relative lipid proportion. Affects LNP structure, RNA encapsulation, and biological performance. Warning: Sum of molar ratios must equal 100%.
    (%)

    Warning: Sum of molar ratios must equal 100%.

    Mass to collect info Lipid mass needed for formulation, based on total lipid concentration and molar ratios.
    (mg)
    -

    Lipid 4:

    Lipid 4 * info Core LNP components: structural, sterol, ionizable, and PEGylated lipids. Each impacts RNA delivery.
    Type info Defines lipid function: structural (stability), sterol (fluidity), ionizable (RNA binding), PEG (circulation).
    PEG-Lipid
    N info Protonatable amine groups per lipid. Critical for RNA binding and endosomal escape.
    (number)
    0
    Molar weight info Lipid molecular weight (g/mol). Used to calculate molar concentrations in the final formulation.
    (g/mol)
    -
    Molar ratio * info Relative lipid proportion. Affects LNP structure, RNA encapsulation, and biological performance. Warning: Sum of molar ratios must equal 100%.
    (%)

    Warning: Sum of molar ratios must equal 100%.

    Mass to collect info Lipid mass needed for formulation, based on total lipid concentration and molar ratios.
    (mg)
    -

    Lipid 1:

    Stock solution info Lipid concentration in solvent (e.g., ethanol). Defines volumes required for formulation.
    (mg/mL)
    Volume to sample info Lipid stock volume needed to obtain the correct lipid amount for LNP preparation.
    (µL)
    -

    Lipid 2:

    Stock solution info Lipid concentration in solvent (e.g., ethanol). Defines volumes required for formulation.
    (mg/mL)
    Volume to sample info Lipid stock volume needed to obtain the correct lipid amount for LNP preparation.
    (µL)
    -

    Lipid 3:

    Stock solution info Lipid concentration in solvent (e.g., ethanol). Defines volumes required for formulation.
    (mg/mL)
    Volume to sample info Lipid stock volume needed to obtain the correct lipid amount for LNP preparation.
    (µL)
    -

    Lipid 4:

    Stock solution info Lipid concentration in solvent (e.g., ethanol). Defines volumes required for formulation.
    (mg/mL)
    Volume to sample info Lipid stock volume needed to obtain the correct lipid amount for LNP preparation.
    (µL)
    -
    Solvent to supplement info Extra solvent volume required to reach the target lipid concentration.
    (µL)

    Warning: Stock solutions too dilluted to reach target lipid concentration.

    -

    D. Calculator results

    Total concentration of lipids in your initial lipid mix info Lipid concentration in the organic phase before mixing. Determines RNA encapsulation and LNP stability.
    -
    Initial RNA concentration in aqueous buffer info Concentration of the RNA phase before mixing. Determines final RNA content in LNPs.
    (µg/mL)
    -
    RNA weight per sample info Total RNA mass in the final LNP formulation, based on concentration and volume.
    (mg)
    -

    E. Save results in pdf and xls

    Send your calculations straight to your inbox in XLS and PDF files.

    You'll also get a link to reopen the calculator with your data pre-filled —no need to start over!

      This Calculator is still in beta
      We’re learning fast, and your feedback means everything!

      We’re exploring new features like PDF exports, print-friendly formats for your lab notebook, and even pre-filled lipid mixes inspired by Moderna or Pfizer. No promises yet — but lots of ideas on the table. And if you have ideas for this Calculator (or others you’d love to see), we’d love to hear them!

      For now, you can already send your results by email and get a custom link to reload your exact formulation anytime.


      Big thanks to the team at Inside Therapeutics for crafting this tool — and to you, for pushing RNA-LNP research forward. We hope it makes your life just a little easier.

      Looking to improve your RNA-LNP formulation?
      Discover our LNP Formulation system

      Discover TAMARA
      LNP Formulation Inside Therapeutics Contact

      Tried the Calculator? Tell us what you think!

      Spotted a bug? Got an idea? We’re all ears!