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Welcome to the free online scientific calculator with units conversions


Also complex math included.

Calculator input expression:

or extend the URL with your calculator input expression to get the result.

Some calculator input expression exampes:


Full list of input syntax resources:

# ----------
# Base Units
# ----------

base_units = ['kg', 'm', 's', 'A', 'K', 'mol', 'cd',
              'rad', 'sr', '%', 'dB', 'bit']

# ---------
# Constants
# ---------

# pi, e, j

# ---------
# Functions
# ---------

# abs, int, sqrt, ln, log, sin, asin, cos, acos, tan, atan, frac

# -------------
# Special Units
# -------------


# percent, % = pc
def to_pc(x):
    "to_pc(50/100)=50*%, (50*pc)/pc=50, anything+50*pc=1.5*anything"
    return 100*x*pc


# dB
def to_dB(x):
    "to_dB(2)=~3*dB, (3*dB)/dB=~2, (3*dB).dB=3, anything+3*dB=~2*anything"
    return 10*log(x)*dB


# dBm and dBW, unit of power (W)
dBm = quantity('dBm', [0]*len(base_units))
dBW = quantity('dBW', [0]*len(base_units))

# Celsius
degC = quantity('degC', [0]*len(base_units))  # absolute temperature
dC = K  # relative temperature, for summing and subtraction
# Example: 20*degC+10*dC = 303.15*K, while 20*degC+10*degC = 576.3*K

# Fahrenheit
degF = quantity('degF', [0]*len(base_units))  # absolute temperature
dF = 5*K/9  # relative temperature, for summing and subtraction


# Quantities may be given in any unit with Quantity.unit('any_unit')
# Example: (55*mph).unit('km/h') = '88.51391999999997*km/h'

# --------
# Prefixes
# --------

Y_ = 1e24
Z_ = 1e21
E_ = 1e18
P_ = 1e15
T_ = 1e12
G_ = 1000000000
M_ = 1000000
k_ = 1000
h_ = 100
da_ = 10
d_ = 0.1
c_ = 0.01
m_ = 1e-3
u_ = 1e-6
n_ = 1e-9
p_ = 1e-12
f_ = 1e-15
a_ = 1e-18
z_ = 1e-21
y_ = 1e-24

# Binary Prefixes
Ki_ = 2**10
Mi_ = 2**20
Gi_ = 2**30
Ti_ = 2**40
Pi_ = 2**50
Ei_ = 2**60

# -------------
# Derived Units
# -------------

# Dimensionless
pm = m_*100*pc          # permille
ppm = u_*100*pc         # parts per million
ppb = n_*100*pc         # parts per billion
ppt = p_*100*pc         # parts per trillion

Np = 20*log10(e)*dB     # Neper

mrad = m_*rad
rev = 2*pi*rad          # revolution
deg = pi/180*rad
amin = deg/60           # arcminute
asec = amin/60          # arcsecond
# radians.dms returns in revs, degrees, arcmins and arcsecs. Example:
# (10*rad).dms = 1*rev + 212*deg + 57*amin + 28.0624709636525*asec

B = 2**3*bit            # Byte
Kibit = Ki_*bit
MiB = Mi_*B
GiB = Gi_*B

# Mass
g = kg/k_
mg = m_*g
ug = u_*g
Mg = M_*g
t = Mg                  # metric ton
lb = 0.45359237*kg      # Pound, avoirdupois (exact)
oz = lb/16              # Ounce
st = 14*lb              # Stone

# Length
fm = f_*m
pm = p_*m
nm = n_*m
um = u_*m
mm = m_*m
cm = c_*m
dm = d_*m
km = k_*m
Mm = M_*m
nmi = 10*Mm/(60*90)      # Nautical Mile
Å = 1e-10*m
in_ = 25.4*mm
mil = m_*in_
ft = 12*in_
yd = 3*ft
mi = 1760*yd

# Area
b = 100*fm**2           # Barn
ha = (h_*m)**2          # Hectare
ac = 66*ft*660*ft       # Acre

# Volume
L = dm**3
uL = u_*L
mL = m_*L
cL = c_*L
dL = d_*L
cc = cm**3

tbsp = 15*mL            # Tablespoon
tsp = tbsp/3            # Teaspoon

galUS = 231*in_**3      # US gallon
ptUS = galUS/8          # US pint
flozUS = ptUS/16        # US fluid ounce
cupUS = ptUS/2          # US cup
cupLUS = 240*mL         # US legal cup
tbspUS = flozUS/2       # US tablespoon
tspUS = tbspUS/3        # US teaspoon

galI = 4.54609*L        # Imperial gallon (exact)
ptI = galI/8            # Imperial pint
flozI = ptI/20          # Imperial fluid ounce
tbspI = flozI*5/8       # Imperial tablespoon
tspI = tbspI/3          # Imperial teaspoon

tbspAu = 20*mL          # Australia tablespoon

tbspCa = flozI/2        # Canada tablespoon
tspCa = tbspCa/3        # Canada teaspoon

# Time
ps = p_*s
ns = n_*s
us = u_*s
ms = m_*s
mn = 60*s               # minute
h = 60*mn
dy = 24*h
wk = 7*dy
yrJ = 365.25*dy         # Julian year
yrG = 365.2425*dy       # Gregorian year
monthJ = yrJ/12         # Average month in Julian year
# seconds.hms returns weeks, days, hours and seconds. Example:
# (1e6*s).hms = 1*wk + 4*dy + 13*h + 46*mn + 40.0*s
# HH:MM returns HH*h + MM*mn

# Speed
kt = nmi/h              # knot
knot = kt
kph = km/h
mph = mi/h              # miles per hour

# Inv Time
Bq = 1/s
Hz = 1/s
mHz = m_*Hz
kHz = k_*Hz
MHz = M_*Hz
GHz = G_*Hz
rpm = 1/mn              # revolutions per minute
kc = kHz
mc = MHz

# Force
N = kg*m/s**2
uN = u_*N
mN = m_*N
kN = k_*K
MN = M_*N

# Power
W = N*m/s
mW = m_*W
kW = k_*W
MW = M_*W

# Energy
J = N*m
kJ = k_*J
MJ = M_*J
Ws = W*s
kWh = kW*h

# Radiation Dose
Gy = J/kg
Sv = J/kg

# Pressure
Pa = N/m**2
hPa = h_*Pa
kPa = k_*Pa
MPa = M_*Pa
bar = 100*kPa
mbar = m_*bar

# Electric Current
uA = u_*A
mA = m_*A
kA = k_*A

# Charge
As = A*s
C = As
mC = m_*C
kC = k_*C
mAh = m_*A*h

# Voltage
V = J/C
uV = u_*V
mV = m_*V
kV = k_*V
MV = M_*V

# Resistance
ohm = V/A
kohm = k_*ohm
Mohm = M_*ohm

# Conductance
S = 1/ohm

# Capacitance
F = C/V
mF = m_*F
uF = u_*F
nF = n_*F
pF = p_*F

# Magnetic Flux
Wb = V*s

# Inductance
H = Wb/A
mH = m_*H
uH = u_*H
nH = n_*H

# Magnetic Flux Density (B)
T = Wb/m**2

# Magnetic Field Intensity (H)
Oe = 1000/(4*pi)*A/m

# Catalytic Activity
katal = mol/s

# Luminous Flux
lm = cd*sr

# Illuminance
lx = lm/m**2

# --------------------------------
# Physical constants and standards
# --------------------------------

G = 6.6743e-11*m**3*kg**-1*s**-2    # Universal Gravitational Constant
g0 = 9.80665*m/s**2                 # Standard Gravity (exact)
atm = 101325*Pa                     # Standard Atmosphere (exact)
c0 = 299792458*m/s                  # Speed of Light (exact)
hP = 6.62607015e-34*J*s             # Planck Constant (exact)
_hP = hP/(2*pi)                     # Reduced Planck Constant
u0 = 1.25663706212e-6*H/m           # Vacuum Permeability
e0 = 1/(u0*c0**2)                   # Electric Constant
qe = 1.602176634e-19*A*s            # Elementary Charge (exact)
me = 9.10938356e-31*kg              # Electron Mass
mp = 1.672621898e-27*kg             # Proton Mass
u = 1.6605390666e-27*kg             # Atomic Mass unit
kB = 1.380649e-23*J/K               # Boltzmanns Constant (exact)
sc = pi**2*kB**4/(60*_hP**3*c0**2)  # Stefan-Boltzmann Constant (sigma)
NA = 6.02214076e23/mol              # Avogadro Constant (exact)
Rg = NA*kB                          # Gas Constant
Fc = qe*NA                          # Faraday Constant

# ---------------------------------
# Derived Units II,
# (dependent on physical constants)
# ---------------------------------

# Length
ly = yrJ*c0                 # Light-year

# Force
kgf = kg*g0                 # Kilogram-force
lbf = lb*g0                 # Pound-force

# Power
hpI = 33000*ft*lbf/mn       # Mechanical (Imperial) horsepower
hpM = 75*g0*kg*m/s          # Metric horsepower
hpE = 746*W                 # Electric horsepower

# Energy
eV = qe*V                   # Electronvolt
meV = m_*eV
keV = k_*eV
MeV = M_*eV

cal = 4.184*J               # Thermochemical Calorie (exact),
                            # (water spec heat capacity ~4.184 J/(g*K) )
kcal = k_*cal

cal_IT = 4.1868*J           # Steam Table Calorie (exact)

BTU_Th = cal*dF/K*lb/g      # British Thermal Unit (Thermochemical variant)
BTU = cal_IT*dF/K*lb/g      # British Thermal Unit (Steam Table variant)
BTU_ISO = round(BTU, 2)     # British Thermal Unit (ISO 31-4 variant)

# Pressure
at = kgf/cm**2              # Technical atmosphere
Torr = atm/760
mmHg = 133.322387415*Pa     # (defined exact)
psi = lbf/in_**2            # Pound-force per square inch

2024-02-23 14:30:52 CET
CPU temp = 28 °C