Free Online Biochemistry & Chemistry Tools
A growing collection of browser-based tools for DNA sequence analysis and chemistry calculations — molar mass, molarity, dilution, pH, equation balancing, an interactive periodic table, and more. No installs, no sign-up — just open and use.
All Tools
DNA Reverse Complement
Compute the reverse complement of a DNA sequence (A↔T, C↔G) instantly.
View all →GC Content Calculator
Calculate the GC content percentage and base composition of a DNA sequence.
View all →DNA Base Counter
Count the occurrence of each nucleotide (A, T, C, G) in a DNA sequence.
View all →DNA Sequence Cleaner
Clean a DNA sequence by removing whitespace, numbers, and non-standard characters.
View all →DNA to RNA Transcription
Transcribe a DNA sequence into RNA by replacing thymine with uracil (T→U).
View all →Cell Culture Calculator
Cell counting (hemocytometer), seeding volume, split ratio, and viability — common cell culture calculations.
View all →Plasmid Designer
Upload a GenBank/FASTA plasmid, draw a circular map, annotate restriction sites, and export PNG/SVG.
View all →Molar Mass Calculator
Calculate the molar mass of a compound from its chemical formula (e.g. H2O, NaCl).
View all →Molarity Calculator
Calculate molarity from solute mass, molar mass, and solution volume.
View all →Dilution Calculator
Calculate dilution using the C1V1 = C2V2 formula. Solve for any variable.
View all →Solution Preparation Calculator
Calculate the mass of solute needed to prepare a solution of given molarity.
View all →Percent Solution Calculator
Calculate percent concentration (w/w, w/v, v/v) of a solution.
View all →Interactive Periodic Table
Browse all 118 elements. Click any element to view atomic weight, electron configuration, oxidation states, density, and melting point.
View all →Unit Converter
Convert between metric units for mass (g, mg, μg, ng), volume (L, mL, μL), and concentration (M, mM, μM, nM).
View all →Concentration Converter
Convert between mg/mL and mM (molar concentration) using molar mass.
View all →Formula Parser
Parse a chemical formula and view element composition, atom counts, and mass contributions.
View all →Chemical Equation Balancer
Balance a chemical equation automatically. Find stoichiometric coefficients (e.g. H2 + O2 -> H2O).
View all →pH Calculator
Calculate pH from [H⁺], or from pKa for weak acids and buffers (Henderson-Hasselbalch).
View all →Buffer Calculator
Design a buffer solution using the Henderson-Hasselbalch equation. Compute the [A⁻]/[HA] ratio, concentrations, moles, and masses.
View all →Centrifuge RPM ↔ RCF Converter
Convert between centrifuge RPM and relative centrifugal force (RCF, × g) using the rotor radius.
View all →Serial Dilution Calculator
Calculate concentration at each step of a serial dilution. Supports dilution factor and step count, with optional per-step volume.
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