Convert 1 Optimism (OP) to Old Sierra Leonean Leone (SLL)

Convert Optimism to old Sierra Leonean leones at the live mid-market rate. Reverse: SLL to OP

The Old Sierra Leonean Leone is no longer in use

Old Sierra Leonean Leone (SLL) was replaced by the Sierra Leonean Leone (SLE) in 2022. For today’s money, convert OP to SLE.

Amount

From

1 Optimism =

3,076.63 SLL −2.00% today

1 OP = 3,076.63 SLL · 1 SLL = 0.00032503 OP

Mid-market rate, updated 09:20 UTC. Paid plans update as often as every 60 seconds. Get OP→SLL rates via API

OP to SLL over the last year

52-week high: 17,208.75
52-week low: 1,875.50
52-week average: 4,541.67
Change over the year: −81.26%

Conversion tables

OP to SLL
OP	SLL
1 OP	3,076.63 SLL
10 OP	30,766.27 SLL
100 OP	307,662.69 SLL
1,000 OP	3,076,626.88 SLL
10,000 OP	30,766,268.84 SLL
50,000 OP	153,831,344.20 SLL
100,000 OP	307,662,688.41 SLL

SLL to OP
SLL	OP
1 SLL	0.000325 OP
10 SLL	0.00325 OP
100 SLL	0.0325 OP
1,000 SLL	0.325 OP
10,000 SLL	3.25031300 OP
50,000 SLL	16.25156500 OP
100,000 SLL	32.50313000 OP

Get OP→SLL rates via API

The live rate, the rate on any past day or a whole range, for SLL and 170+ other currencies, as JSON. Free plan included. See the exchange rate API.

Get a free API key API documentation

curl https://api.currencyapi.com/v3/latest \
  -G -d base_currency=OP -d currencies=SLL \
  -H "apikey: YOUR-API-KEY"

# the rate on a past day
curl https://api.currencyapi.com/v3/historical \
  -G -d base_currency=OP -d currencies=SLL \
  -d date=2025-10-04 \
  -H "apikey: YOUR-API-KEY"

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Questions about OP to SLL

How much is 1 OP in SLL?

1 Optimism is 3,076.63 old Sierra Leonean leones at the mid-market rate of 4 October 2026, 09:20 UTC, when 1 OP = 3,076.63 SLL.

What was the OP to SLL rate over the last year?

Over the last 52 weeks 1 OP ranged from 1,875.50 to 17,208.75 SLL, 4,541.67 SLL on average.

Which exchange rate is this?

The mid-market rate: the midpoint between what currency markets pay and ask for OP/SLL, without the margin a bank or card issuer adds, so the rate you are charged is usually a little worse.